John said that someone greater than him would soon come who would enable some of the people to change their lives and who would severely punish the others.

Matthew 3:11-12

11 “As for me, I am not very important, because I baptize you only with water. I baptize you because of your feeling sorry that you have sinned. But someone else will come soon who is very great; he will do powerful deeds (OR, act powerfully). Because he is superior to me, I am not worthy even to do a menial task for him, such as to carry his sandals.

He will put his Holy Spirit within you to truly change the way you live [MET], and he will judge others of you and punish you in the fire in hell. 12 He is like a farmer who wants to clear away the grain that is on the ground where it has been threshed {they have threshed it}. That farmer uses a huge fork to throw the grain into the air to separate the wheat from the chaff [MET], and then he cleans up the threshing area. Similarly, God will separate righteous people from the evil people like a farmer who gathers the wheat into his storage area, and then God will burn the people who are like chaff with a fire that will never be put out [MET].”