A Dweam Within Dweam it has become more and more obvious to me that the typical way in which debates take place on the Internet does very little to change the minds or aid in understanding people of different theological persuasions. There are problems that hinder understanding caused by lack of focus and other problems caused by being too narrowly focused.
Typical debate centers chiefly around external practice. Should babies be baptized? What qualifies as a valid baptism? When a Lutheran and a Baptist debate (or just about anyone from two distinct theological positions) it's almost impossible to get anywhere because both parties have a list of several ideas in their minds that each contribute to the respective position. For the Baptist, baptism is all about someone who has already made a profession of faith is now making a personal testimony that he or she is a Christian by being immersed in water. Whatever arguments you might make for the baptism of infants are lost on them because they are absolutely convinced that to baptize means "immerse" and you are not immersing and are obviously wrong in your practice. For a Lutheran a valid baptism consists of God's Word joined with the water. A person receives a valid baptism even if that does not believe. The baptismal formula is of great importance to the validity of baptism for a Lutheran but plays little to no role in the validity of baptism for a Baptist. Our minds are incapable of handling several aspects that play in to whether or not we should baptize the baby at the same time. The Baptist is generally incapable of conceiving of a baptism that does not involve both profession of faith by the person being baptized and immersion. It is impossible to have a meaningful conversation with a Baptist on what baptism is without discussing the proper recipients, mode, and meaning of baptism. But it is equally impossible to have a meaningful conversation about baptism while trying to discuss all these things at the same time. There must be a systematic progression that takes the debate through recipients, mode, and meaning without trying to deal with them them simultaneously. Otherwise we just keep the old Adam happy by reinforcing his tendency to think that other people believe differently just because they are idiots. There are reasons for why people believe what they do. Those reasons aren't always good but they should be honestly evaluated.
There are deeper presuppositions that stand behind beliefs about proper recipients, mode, and meaning. Baptism is only one example. The same holds true for any other issue. The person holding to a particular belief about the meaning of baptism may not in fact even be consciously aware of the presuppositions that they hold to. Opposition to baptismal regeneration, for instance, is often the result of several different presuppositions. The Baptist Greek grammarian, A.T. Robertson, has to admit that the most natural way to read the Greek of Acts 2:38 results in the teaching that we receive the forgiveness of sins through baptism. However, he opposes this teaching because he believes the teaching of baptismal regeneration to be in conflict with other passages of Scripture. Specifically, he says that baptism is a work and the Scriptures teach that we are not saved by works. In order to have a meaningful debate with a Baptist on the issue of baptismal regeneration, it is necessary to debate the issue of whether the Scriptures teach that baptism is our work or God's work. This will inevitably lead to discussions about how God works faith in us. Most Baptists will acknowledge that God works faith in us through the preaching of the Word but will deny that God works faith in us through baptism. In the mind of the Lutheran, baptism is God's Word in and with the water and adding water to God's Word doesn't in any way destroy God's Word. In the mind of the Lutheran, God's Word simply does what it says. In the mind of the Baptist, as seen in the writings of A.T. Robertson and others, God's Word commissions the baptism but has nothing to do with the actual baptism. The actual baptism is an immersion and this immersion takes place because God commanded that the immersion takes place. But the baptismal formula only commissions the baptism, it's not strictly speaking part of the baptism in the mind of the Baptist.
If you argue long enough, you will find that part of the Baptist opposition to baptismal regeneration is tied to their belief in either the Perseverance of the Saints or Once Saved Always Saved. It becomes necessary to address these issues in order for debate to continue. Often these beliefs are not explicitly stated and require further questions to uncover or both parties will end up talking past one another. The key is to carefully listen and try to determine what the person's real concerns are. The other party might say something like, "If baptismal regeneration were true there wouldn't be people like Christopher Hitchens." What the person means is that Christopher Hitchens died as an unbeliever and this would be impossible if the person was truly regenerated in baptism. The Scriptures point pretty clearly to examples of people who showed they had faith but fell away from the faith. Some are restored again and others are not. Peter makes his great confession that Jesus is the Christ, but then acts as the mouthpiece of Satan trying to persuade Jesus not to be crucified, denies Christ, and denies the resurrection. In fact Jesus tells the Apostles prior to his death that they will all fall away (Mark 14:27). The Baptist will tell you that this was before the Holy Spirit was given to Peter or that this was some non-salvific sort of falling away or produce some other explanation. Often 1 John 2:19 is quoted: "They went out from us, but they were not of us; for if they had been of us, they would have continued with us. But they went out, that it might become plain that they all are not of us." John's point is that these false teachers that he is referring to never held to the true faith to begin with but the Baptist/Calvinist interprets this passage as referring to every individual who ultimately falls away from the faith. If someone ultimately falls away they take that to mean that the person was never "saved" to begin with. They then get around passages which seem to refer to the person as having faith by using adjectives to speak of "historical" faith or some other kind of faith that is not "saving" faith.
The possibility that you are able to get this deep in a conversation with someone is unfortunately pretty low. But if you were able to do so another remarkable phenomena would occur. All the endless branches that are the cause of the single external practice will work their way down into one single root. In The Religious Bodies of America by F.E. Mayer, Mayer describes the formal and material principles of the various divisions in Christianity. The formal principle is the source of doctrinal authority. Most Protestant bodies will regard the Scriptures as the sole source of doctrinal authority. The material principle is the central teaching of a religious body. In Calvinistic church bodies, the material principle is the glory of God. In Lutheranism the material principle of justification by faith in Christ alone. Things get a little more complicated in Baptist theology. More Calvinist Baptists will have the glory of God as their material principle. Others may have the Lordship of Christ as their material principle. This single material principle will lead to all the other doctrines unique to that religious body. Things would be much simpler if we could simply spend our time debating what the proper material principle is, but it's often difficult to convince people that they have a material principle. They say things like, "We just teach the Bible." People are often unaware of the presuppositions that they have when they come to a Biblical text. The old Adam would have us put greater trust in our reason than in the Scriptures. Sometimes without even realizing it, we assume things the text does not actually say because we trust our reason more than Scripture. The text might say "Be baptized for the forgiveness of sins" but we think it can't possibly mean what it sounds like it means. We discard the faith of the child for the unbelief of the grown-up.
The Scriptures themselves direct us to a material principle. Jesus said the Scriptures are all about Jesus. Paul said He preached nothing but Christ-crucified. Christ-crucified is the material principle that Paul gives us. We are justified through faith alone in Christ-crucified. If we abandon the guidance of Scripture we can easily become convinced that "God's glory" is the central teaching. We will concoct all kinds of teachings derived from this bad starting point. When we are tempted to put faith in our logical inferences derived from bad material principles we must remember that God's ways are not our ways and His thoughts are not our thoughts. There is nothing reasonable about Christ-crucified. Our realization that our salvation is completely dependent on Christ-crucified should humble us and give us patience to deal with those who are having trouble seeing their own presuppositions that color their reading of Scripture.