Mark 1:4

John the Baptizer appeared in the desert and was preaching a baptism conditioned on repentance to obtain the forgiveness of sins.

Luke 1:77

to give His people the knowledge of salvation through the forgiveness of their sins.

Matthew 3:1-2

In those days John the Baptist appeared, and kept preaching in the desert of Judea,

Matthew 3:6

and were baptized by him in the Jordan River, as one by one they continued to confess their sins.

Matthew 3:11

I am baptizing you in water to picture your repentance. But He that is coming after me is stronger than I am, and I am not fit to carry His shoes. He will baptize you in the Holy Spirit and in fire;

Luke 3:2-3

in the high priesthood of Annas and Caiaphas, the message of God came to John, the son of Zechariah, in the desert.

John 3:23

But John too was baptizing people at Aenon, near Salim, for there was plenty of water there, and so the people were coming and being baptized.

Acts 10:37

You know the story yourselves that spread all over Judea, beginning from Galilee after the baptism that John preached,

Acts 13:24-25

as John, before His coming, had already preached baptism as an expression of repentance, for all the people of Israel.

Acts 19:3-4

He then asked, "With what sort of baptism then were you baptized?" They answered, "With John's baptism."

Acts 22:16

And now, why are you waiting? Get up and be baptized and wash your sins away by calling on 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
In those days John the Baptist appeared, and kept preaching in the desert of Judea,
Luke 3:2
in the high priesthood of Annas and Caiaphas, the message of God came to John, the son of Zechariah, in the desert.
John 3:23
But John too was baptizing people at Aenon, near Salim, for there was plenty of water there, and so the people were coming and being baptized.
Acts 10:37
You know the story yourselves that spread all over Judea, beginning from Galilee after the baptism that John preached,
Acts 13:24
as John, before His coming, had already preached baptism as an expression of repentance, for all the people of Israel.
Acts 19:3
He then asked, "With what sort of baptism then were you baptized?" They answered, "With John's baptism."

Remission

Acts 22:16
And now, why are you waiting? Get up and be baptized and wash your sins away by calling on His name.'