Mark 1:4

So John the Baptizer came, and was in the Desert proclaiming a baptism of the penitent for forgiveness of sins.

Luke 1:77

To give to His People a knowledge of salvation In the forgiveness of their sins,

Matthew 3:1-2

About this time John the Baptist made his appearance, preaching in the Desert of Judaea.

Matthew 3:6

and were baptized by him in the Jordan, making full confession of their sins.

Matthew 3:11

I indeed am baptizing you in water on a profession of repentance; but He who is coming after me is mightier than I: His sandals I am not worthy to carry for a moment; He will baptize you in the Holy Spirit and in fire.

Luke 3:2-3

during the High-priesthood of Annas and Caiaphas, a message from God came to John, the son of Zechariah, in the Desert.

John 3:23

And John too was baptizing at Aenon, near Salim, because there were many pools of water there; and people came and received baptism.

Acts 10:37

the story, I mean, which has spread through the length and breadth of Judaea, beginning in Galilee after the baptism which John proclaimed.

Acts 13:24-25

Before the coming of Jesus, John had proclaimed to all the people of Israel a baptism of repentance.

Acts 19:3-4

"Into what then were you baptized?" he asked. "Into John's baptism," they replied.

Acts 22:16

And now why delay? Rise, get yourself baptized, and wash off your sins, calling upon His name.'

Treasury of Scripture Knowledge

Summary

John did baptize in the wilderness, and preach the baptism of repentance for the remission of sins.

Remission

Bible References

Did

Matthew 3:1
About this time John the Baptist made his appearance, preaching in the Desert of Judaea.
Luke 3:2
during the High-priesthood of Annas and Caiaphas, a message from God came to John, the son of Zechariah, in the Desert.
John 3:23
And John too was baptizing at Aenon, near Salim, because there were many pools of water there; and people came and received baptism.
Acts 10:37
the story, I mean, which has spread through the length and breadth of Judaea, beginning in Galilee after the baptism which John proclaimed.
Acts 13:24
Before the coming of Jesus, John had proclaimed to all the people of Israel a baptism of repentance.
Acts 19:3
"Into what then were you baptized?" he asked. "Into John's baptism," they replied.

Remission

Acts 22:16
And now why delay? Rise, get yourself baptized, and wash off your sins, calling upon His name.'