Question

Where did John the Baptist receive authority to baptize?

Answer

From God.

And when all the people heard Him, even the tax collectors justified God, having been baptized by John. but the Pharisees and lawyers rejected the will of God for themselves, not having been baptized by him (Luke 7:29-30)

The purpose of the work of John was to prepare Israel for the coming of Christ (Isaiah 40:3; Malachi 3:1; Matthew 3:1-3; Mark 1:1-3; Luke 3:1-6). He did this by proclaiming the approaching kingdom of God, calling upon the people to repent so they would be believe in Christ when He came, pointing them to Christ, and baptizing them in water unto repentance for the remission of sins (Matthew 3:4-12; Mark 1:4-8; Luke 3:1-18; John 1:6-7,15,19-34).

When Christ came John directed his own disciples to Christ (John 1:36-37; 3:23-30). John specifically testified of Jesus Christ, “He must increase, but I must decrease” (John 3:30).

Once baptism in the name of Jesus Christ was proclaimed by divine authority (Acts 2:38), those who had received John’s baptism needed to be baptized in His name, i.e., by His authority (Acts 19:1-5). Today only one baptism has divine authority, baptism in the name of Jesus Christ (Ephesians 4:4-6).