Believer’s baptism is a common expression in Christian circles.

1. It is not a biblical phrase.
2. What is meant by ‘believer’? Usually this expression means a person who is “born again”.  So far so good.  What about someone who is not born again?  Can they not be baptized?  Not usually, according to those who support believer’s baptism.
3. What about a person who believes that Jesus is the Christ, the Son of God, but does not have the assurance that they are born again?  This is the same issue.  Those who support believer’s baptism will not baptize these people even if they are actually born again, because they cannot say so.
4. In other words, the belief in “believer’s baptism” is not faith in Christ but belief in one’s own salvation.  This is assurance of salvation, not the confession of Christ nor of Christianity that is required for Christian baptism.
5. In practice, the belief is not belief in Jesus Christ but believe in one’s own salvation.

So, where does this idea come from? There are various texts of Scripture used to support the idea.  None of them do so.

If Scripture is wrongly interpreted, then the whole force of biblical authority is supporting error.

The Ethiopian eunuch confessed that Jesus Christ is the Son of God Act 8:37 in order to be baptized.  His confession was not about himself nor his assurance of salvation, but about Jesus Christ.  Upon this confession, Philip baptized the Ethiopian eunuch. 

It is time to recover the proper concept of biblical baptism.