According the free church tradition, only those who believe in Christ as Lord should be baptized into the church as members of his body. As such, for this tradition membership in the body of Christ is voluntary. It is not imposed, but rather is given to those who come to baptism out of a desire to follow Christ.
The majority tradition of the Christian faith labels this an unacceptable form of modern voluntarism, claiming that it places the priority on the self-determining autonomy of the human subject rather on the free grace of God. Now, clearly a whole discussion could be had about the nature of grace and how it draws human beings toward the church. Let us leave that aside for the moment.
If we cut through the fog generated by the scare word of “voluntarism,” it seems to me that there are only two possible construes of how baptism ought to go down. If the voluntary baptism of believers is illicit as the normative practice, what is the alternative? The only alternative to voluntary baptism is involuntary baptism, is it not?
Now, everyone agrees that voluntary baptism is acceptable and right. No on is opposed to converts being baptized upon profession of faith. The question, as I see it, must rest on what theological reasons we have for baptizing those who do not believe in Christ and do not have the ability to consent or dissent from baptism? What theological reasons are there for involuntary baptism? That seems to me to be a reasonable question. I have yet to see, theologically, why involuntary baptism should be the norm of the church’s practice.