'Mightier' in the Bible

I indeed baptize you in water unto repentance, but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you in the Holy Spirit and in fire:

And he preached, saying, There cometh after me he that is mightier than I, the latchet of whose shoes I am not worthy to stoop down and unloose.

John answered, saying unto them all, I indeed baptize you with water; but there cometh he that is mightier than I, the latchet of whose shoes I am not worthy to unloose: he shall baptize you in the Holy Spirit and in fire: