Baptism is a symbol for those who do believe. It is not done supposedly for them to become believers; this is clear from Acts 2.41.
Believing in Jesus means that you "
should not perish" (John 3:16)...iffy.
Believing and being baptized means that you "
shall be saved" (Mark 16:16)...much more absolute.
My take on believer's baptism is that you believe and repent and this brings justification.
Sanctification for that believer will be a process from that point forward.
But if, after believing and repenting, you are baptized in the name of Jesus "
for the remission of sins" (Acts of the Apostles 2:38-39)...
That is automatic sanctification for the one who does so in faith.
Their sins go into remission like cancer might go into remission.
They are no longer of consequence....they are not powerful enough in the believer's life to bring about their wages (see Romans 6:23).
The believer who is baptized not only receives remission of sins but is absolutely promised the gift of the Holy Ghost....who is power to live the Christian life...and remission of sins is closely interconnected with this reality...because for the one who has "
faith in the operation of God" (Colossians 2:12 (kjv)), sanctification can be accomplished in a very complete sense...as it is written in 1 Thessalonians 5:23-24, Hebrews 10:14, and 1 John 3:9; Jude 1:24, 2 Peter 1:10, and 1 John 2:10; 1 John 3:7, 1 John 3:3, and 1 John 2:6.
The person can begin to walk in freedom from sin (John 8:31-36) and victory over sin (1 Corinthians 15:57).
Of course there must be real repentance preceding the baptism in Jesus' name for the remission of sins.
Repentance is what most would call salvation...
But really, remission of sins is promised when, after believing and repenting, you are baptized in the name of Jesus for the same.
You can wait for years of a process what the Lord wants to give you in a moment of time...and if you opt for the process, you may never reach "
the measure of the stature of the fulness of Christ" (Ephesians 4:13).
But there is indeed a "magic" in the promise....
In fulfilling the conditions of the promise in Acts of the Apostles 2:38-39, God will be sure to give to you the promise associated with those conditions..."
remission of sins" and "
the gift of the Holy Ghost" (see also Acts of the Apostles 5:32).