This baptism took the form of complete immersion, the symbolism being that every part of the convert’s former self had to be washed away. What was distinctive about John the Baptist’s baptism is that it was administered to Jews as well as Gentiles. John baptised to repentance: he considered that the Jews of his day were as much in need of conversion to the values of the kingdom that was at hand as Gentiles.
John’s baptising in the Jordan could have been seen by his Jewish contemporaries as a ‘re-play’ of Israel’s crossing of the Jordan before entering the promised land, but now marking the entry into the new ‘promised land’ about to be inaugurated by Jesus. Also, John, in his style of dress and manner of life, would have evoked both Elijah, who parted the waters of the Jordan, and Elisha, who bade the Gentile, Naaman to bathe in the Jordan for his healing.