Mark 1:4

Amplified Bible

John the Baptist appeared in the wilderness preaching a baptism of repentance for the forgiveness of sins [that is, requiring a change of one’s old way of thinking, turning away from sin and seeking God and His righteousness].

Cross References

Matthew 3:11

“As for me, I baptize you with water because of [your] repentance [that is, because you are willing to change your inner self—your old way of thinking, regret your sin and live a changed life], but He (the Messiah) who is coming after me is mightier [more powerful, more noble] than I, whose sandals I am not worthy to remove [even as His slave]; He will baptize you [who truly repent] with the Holy Spirit and [you who remain unrepentant] with fire (judgment). [Luke 3:16]

Matthew 3:6

and they were being baptized by him in the Jordan River, as they confessed their sins.

Mark 1:5

And all the country of Judea and all the people of Jerusalem were continually going out to him; and they were being baptized by him in the Jordan River, as they confessed their sins.

Luke 1:77

To give His people the knowledge of salvation By the forgiveness of their sins,

John 3:23

Now John was also baptizing at Aenon near Salim, because there was an abundance of water there; and people were coming and were being baptized—

Acts 10:37

you know the things that have taken place throughout Judea, starting in Galilee after the baptism preached by John—

Acts 22:16

Now, why do you delay? Get up and be baptized, and wash away your sins by calling on His name [for salvation].’