Rebuilding the Foundations
I was asked by email how I would conduct a baptism. The writer was careful to add that he "knew" the early Christians dunked a person three times and preferred to use living (flowing) water.
He is probably right on what the early Christians did. The Didache (before AD 150), Tertullian's tract on baptism (c. AD 200), and some of the other early Christian writings spell it out pretty well. Nonetheless, here is how I chose to answer.
If I were starting from scratch, building a church from nothing like the apostle Paul did, I would do what I know. I would ask the convert if he/she believed in God the Father, Creator of everything. When they said yes, I would douse them the first time, preferably in a river, but following the Didache's instructions if one is not available.
Second, I would ask them if they believe in Jesus, the Messiah/Christ/King and Son of God. I would include whatever specific things I felt I needed to include in order to make sure they were confessing the one and only Jesus who rose from the dead, ascended to the right hand of the Father, and is the High Priest of our confession. Then I would douse them a second time.
Finally, I would ask them if they believe in the Holy Spirit, then douse them a third time.
Afterward, I would lay hands on them and pray for them to receive the Holy Spirit. As a flourish that I don't think is apostolic, but that I do think is an excellent picture, I would give them milk mixed with honey to drink, and I would drink it with them.
That said, I believe the unity and growth together of the local church is far more important than the mode, method, and words of baptism. Thus, in the real world, my view is that baptism should be performed the way the local church has decided to do it. I think the revelation of the Holy Spirit in the local church (1 Jn. 2:26-27; 1 Tim. 3:15) is more important and more trustworthy than an individual's study of Scripture and history, as long as the local church consists of people who care about Scripture and their forefathers in the faith. (Most local churches consist of a small percentage of disciples, and are unable to function scripturally or inherit the promises of Scripture.)
So I suppose that my final answer is that if I were gifted to be an apostle, a planter of churches, I would try to do things according to the traditions of the second century churches, which I find to be easier to determine than the traditions of the first century churches. I also think the traditions of the second century churches are more likely to match the traditions of the first century churches (and thus the apostles). However, I am not so gifted, and thus I give myself to pursuing righteousness, faith, love, and peace along with those who call on the Lord out of a pure heart. I diligently work at maintaining the unity of the Spirit, and I trust in God that those of us who have the Spirit can grow together in the faith of our King and in the knowledge of God our Father. In that situation, I would be so glad for someone to be buried in Jesus in baptism and rise to new life in him that I wouldn't care very much about the process we used.
I hope that's not too confusing. Life in this modern world, full of divided Christian clubs claiming to be churches and full of "nominal" Christians that aren't really Christians, things are confusing and difficult. I have found that steadfastly pursuing righteousness, faith, love, and peace with those that call on the Lord out of a pure heart has kept me in as much fellowship as possible and on a steady, devoted path. It even finally led me to people who give themselves wholly to God and do so together.
That was the email I sent. My main point was that I believe decisions about baptism and how it should be done belong to the church, not to any one individual, no matter how gifted or trained he is. The promise of 1 John 2:27 is to lead the church into all truth, not any one individual.
I am wholly convinced that when "the church" consists of, or mostly consists of, disciples working together at obedience to their Master, they will find that Jesus is a faithful teacher who will teach them, one precept at a time, what he wants. As he shows them what he wants from them, he also begins transforming them by his Spirit into a people who can give him what he wants.
This is a much slower process than most people think it will be because most people think they are far more righteous and knowledgeable than they really are.
I am wholly convinced that is the model the apostles both demonstrated and taught, while also giving some basics of "the faith" that were essential to be held to. Those include subjects like the Trinity, the resurrection of the body, and a few others.
Above all, though, the apostles were building a people who would diligently strive to obey Jesus (cf. Matt. 28:19; Tit. 2:13-14), and who would do this together in a heavenly love that testifies to the love of the Father and his Son (Jn. 17:20-23).