This is the third post on sacraments in my ongoing series, theology in bullet points. The first unit in this series had to do with God and Creation (book here), and the second unit was on Christology and Atonement.
We are now in the third and final unit: The Holy Spirit and the Church. The first set of posts in this final unit was on the Holy Spirit. The second set was on the Church. This third set is on sacraments.
Christians have varying perspectives on baptism.
1. Baptism is an area where Christians have disagreed strongly in the days since the Protestant Reformation in the 1500s. But while baptism has arguably been a common feature of Christianity since its beginnings, a person can be saved without being baptized. Accordingly, neither the mode nor the timing of baptism is essential to salvation. This observation puts debates over baptism into the category of "disputable matters" (cf. Rom. 14-15, 1 Cor. 8, 10), and Christians should accordingly be charitable toward each other when it comes to such disagreements.
2. The New Testament records few debates over baptism. The problem in Acts 19:1-7 was that these individuals had only an understanding of John the Baptist. They did not know that Jesus was the Messiah and so had not experienced baptism in the name of Christ. This issue thus does not speak to debates over re-baptism or whether tongues authenticates baptism or over what name/names should be invoked in baptism. 
At Corinth, various parties in the community boasted that their baptism was more significant because of who had led them to believe, including who had baptized them (1 Cor. 1:10-17). These verses seem to indicate, first, that baptism was not a central element in Paul's ministry, at least not at this stage of it. They also indicate what would become clear about three hundred years later in the Donatist controversy of the 300s and 400s: baptism gains no significance from the person who baptizes you.
Christians commonly believe this fact of all the ministries of the Church. The validity and power of God's grace do not depend on the righteousness of the minister. Baptism takes its validity and power from the Holy Spirit and the faith of those involved. If it would turn out that the person administrating baptism is not a believer or if that person is wholly unrighteous, the baptism is still valid because the power comes from God.
3. It is commonly assumed that the earliest church baptized by immersion. This is a reasonable position, given the nature of Jewish miqvaot, the cleansing pools that one finds archaeologically in Jerusalem and its environs. Paul's imagery in Romans 6:4 seems to suggest as much. We are "buried" with Christ in baptism.
However, it is surely significant that the New Testament never makes a point of the method of baptism. Indeed, while baptism is a common feature of the New Testament, the manner by which a person is baptized is never a matter of contention. It thus goes well beyond Scripture to demand that a person must be baptized in a certain way. There are points where we have to address issues that were not raised in the Bible. There are points where biblical teaching is only in a seminal form that can be fleshed out. But the issue of baptism does not seem to be one that we should fight over.
Around the year AD100, someone put together the Didache, a collection of teachings reported to summarize the teaching of the apostles. Although we cannot at all be sure of that claim, it is surely significant that this text is very practical when it comes to baptism. Ideal is a baptism involving immersion in cold, running water (7.2-5). But if it is not possible, then pouring even with warm water is a valid alternative.  Baptisands are also asked to fast for a day or two before undergoing baptism.
Immersion captures the imagery of dying with Christ and complete coverage of one's sins. Sprinkling captures the Old Testament imagery of the altar being sprinkled with blood (e.g., Lev. 16:18-20). But while the Bible may describe various practices, it never prescribes one in relation to baptism.  It is thus not only foolish but unbiblical and counter-Christ to engage in divisive conflict over the mode of baptism.
4. Throughout the vast majority of Christian history, Christians baptized their children as infants. Infant baptism is not explicitly mentioned in the New Testament, although it may very well be inferred in a few passages. In Acts 16:15, Lydia's household is baptized when she believes. Similarly, the whole family of the Philippian jailer is baptized in Acts 16:33. No qualification is given about the age of those baptized. Indeed, no qualification is made about the faith of each individual in the house.
Here we must reckon with the fact that the ancient world consisted of collectivist cultures. That is to say, identity was group-embedded rather than individualistic. This is arguably the default human societal pattern. Homo sapiens is a herd animal. As such, it would be understandable if the decision of a head of household was assumed to be binding on the rest of the household, which would include family members beyond what we call the "nuclear" family, extending even to any slaves in the house.
None of the primary reformers questioned infant baptism.  Luther, Zwingli, and Calvin (not to mention Wesley) all supported infant baptism. Yet it was inevitable that a movement that emphasized justification by individual faith would eventually have some who would argue that baptism should thus take place when a person is old enough to make an individual confession.  This was not a problem for the high Reformers because individuals still expressed their personal faith in confirmation.
Confirmation is the practice of undergoing teaching that leads to an individual confession of faith that "confirms" the faith the Church had for you in baptism. It is a reminder that, even in those traditions which practice infant baptism, that baptism is not sufficient to "save" a person. There must also be a personal confession and owning of faith.
This is the most historic and, perhaps, the preferred approach to Christian baptism. A child is baptized soon after birth, claiming the child for Christ, invoking the faith of the community that surrounds him or her. The child is "in" the Church, and belonging is his or hers to lose. Then when the child is of age, he or she undergoes discipleship in Christian faith and practice, leading to a formal and personal confession of faith before the Church, which can then also be a means of God's grace.
5. However, it is understandable that individualistic cultures would tend to prefer "believer's baptism." Since individualistic cultures emphasize that each individual determines his or her own identity and destiny, it is predictable that they would emphasize a form of baptism that focuses on an individual's confession of faith. Since the New Testament records the first generation of believers, it is understandable that the overwhelming majority of baptisms in the New Testament are adult baptisms. These adult baptisms in Acts easily became the model for baptism in the Americas.
Christians should not de-Christianize each other over such things. It is clear that believer's baptism fit the context of a democratic culture astoundingly well, which is why forms of Baptist Christianity have prevailed in the United States. They did not do so well at first, when in Zurich in the 1500s, some individuals came to Huldrych Zwingli arguing that he had not gone far enough in his reformation. He "baptized" them by drowning in a river. Such de-Christianization of those who practice credobaptism, "believer's baptism" is to be condemned.
Yet, the words of Paul echo toward those who would de-Christianize groups that practice infant baptism as well. "I thank God that I baptized none of you... For Christ did not send me to baptize but to proclaim the gospel" (1 Cor. 1:14, 17). Baptism is thus a disputable matter, one in which the most important thing is charity toward each other, not the timing or mode of the act.
6. Some groups, reacting against the ritualism of the Roman Catholic Church, went so far as to stop the practice of baptism altogether. The chief examples of this, arguably over-reaction are the Quakers and the Salvation Army, which is a branch of Methodism.
On the one hand, we must agree with them that a person can be saved without being baptized. The essential element in crossing from death to life is the working of the Holy Spirit, not baptism. While the thief on the cross was technically still before Christian baptism or the age of the Spirit, Jesus' promise that the thief would join him in Paradise exemplifies well the hope of those who place their faith in Jesus even if they are not baptized.
Yet we argued in the previous article that God uses baptism as a means of grace and that it is the primary act that signifies the inclusion of a person into the community of faith. Why then would we deprive anyone of such blessings? The ritual of non-baptism has itself thus become a "vain ritual" that continues only because of a tradition. It has been five hundred years. There is no more need to protest! Why deprive a part of the body of Christ of a blessing?
Hopefully it is clear that rituals are a key element of human existence. Symbolic acts that we repeat on key occasions are far from empty. They are usually the richest and most powerful memories that we have. Movements that have them will always be exponentially more powerful than those that do not, and we deprive ourselves of such power to our own loss.
Nevertheless, we should not in any way de-Christianize those who do not practice baptism at all.
7. Most importantly, we should receive into our fellowship those who have been baptized in other groups. There is New Testament precedent for baptism in Jesus' name (e.g., Acts 19:5) and in the name of the Father, Son, and Holy Spirit (e.g., Matt. 28:19). Both should be accepted.
Whether a person has been immersed, sprinkled, or poured, we should respect their own conscience and, in a perfect world, we would accept them into our fellowship on the basis of their individual confession of faith, not the particulars of their baptism. To be sure, it is acceptable for individual Christian traditions to baptize in a preferred way. There are enough choices, at least in the West, that we as individuals can worship in a community that baptizes in our preferred way.
The question of re-baptism is a sensitive one. There is no need for a person who was baptized as an infant to be re-baptized. However, Paul would urge us to have our own convictions before God (Rom. 14:22). If it would help a person's faith to be re-baptized, it is in the spirit of Paul to indulge them. We do not want to be a cause of stumbling to anyone, so why would we refuse anyone an opportunity for more grace and an easing of conscience?
What would be far worse is if we sowed seeds of doubt about a person's past baptism. In this case, we are the potential source of the stumbling block. In this case, it is not the individual Christian that needs assurance but it is we who are sowing the seeds of doubt! This is much to be opposed. While the New Testament never fights over the timing or mode of baptism, it strongly opposes any believer who de-Christianizes another over disputable (and in this case even unbiblical) matters such as these.
Ideally, we should think of baptism as a one time act of inclusion. Re-baptism should thus be the exception rather than the rule. And we should not think that a person needs to be re-included into the body of Christ over and over again. True, a person can walk away from Christ. If the break was strong enough, perhaps it could be meaningful to be re-baptized.
What we should not encourage is a sense that a person will move in and out of the family of God repeatedly in their Christian life. Belonging to Christ is not a "one sin you're out" type of situation. Leaving the family of God is possible, but it is not something that happens by chance or casually. We may wrong others in our family and still remain in the family. In the same way, if we practice re-baptism at all, it should be reserved for the most striking of re-entrances.
8. Baptism is a means of grace. It is a sacrament of inclusion, of filling with the Spirit. Christians have practiced baptism since its very beginnings, and it remains a foundational practice today. While we believe it is not necessary for salvation and respect those few traditions that do not practice it, it is a core Christian practice. Let's do it!
However, it is not a practice over which we should de-Christianize others. Its particulars fall, ultimately, into the category of disputable matters. Immersion was perhaps the default New Testament practice, but it was not an absolute. Infant baptism has been the dominant mode throughout Christian history, but credobaptism has obviously been most meaningful to the majority in the individualist West.
Baptism is a sacrament of inclusion into the community of faith, but Christians have varying perspective on its particulars. "Let all be fully convinced in their own minds" (Rom. 14:6). Do not let how you baptize "cause the ruin of one for whom Christ died" (14:15).
Next week: SA4: Communion is a sacrament of re-empowerment.
 Oneness Pentecostals see tongues as a sign of receiving the Holy Spirit and thus question whether someone who has never spoken in tongues is truly saved. Suffice it to say that tongues are not mentioned in every instance of conversion in Acts (e.g., Paul's in Acts 8). How much less, then, is tongues a necessary validation of baptism!
 In the Didache, such pouring is done three times in the name of the Father, and the Son, and the Holy Spirit.
 The lexical fallacy is sometimes committed in arguments over baptism. This fallacy presumes that words have root meanings that are in play in every instance of a word's use. So, someone might argue, that the root bapt- has a connotation of dipping. This may be true in the dark origins of the word group centuries before Christ.
However, words change meanings and develop in their meanings over time. It is fallacious to assume that some root meaning to a word (or original meaning to a word--the etymological fallacy) will always be part of a word's meaning no matter its context. Words just do not work like that.
So in Mark 7:3, it is not clear that the word baptizo has any connotation of how the Pharisees washed their hands. It would seem in this context that the word simply means that they "washed" their hands. A valid translation of baptizo, it would then seem, is "to wash," with no clear connotation of the manner of washing. In the end, since the Didache could speak of a baptisma that involved pouring, it is clear that the word baptism did not include the manner of baptism in its definition at a very early point in Christian history indeed.
 The rise of individualism is indeed part of the rise of Protestantism, and Protestantism fostered the rise of individualism. The two naturally fed off of each other.
 Or, as it is sometimes called, pedobaptism, from the Greek word for child. This contrasts with credobaptism, or "believer's baptism."