Mark 1:9-11 speaks of Jesus and John's first recorded contact.
The "all" of verse 5 includes Jesus both as believing his message and being baptized of him. God at this time fully revealed to John who the Messiah was. However, verses 7-8 make it plain that, before baptizing Jesus, he already knew he was preceding someone. The prophecy given to his father Zacharias (Luke 1:76) had undoubtedly been communicated to him.
Despite the fact that he was no wild man, he was radically alienated from those who were part of the system God had installed during the time of David a thousand years earlier, reestablished under Hezekiah and Josiah, and then later still reinstituted under Ezra following the Jews' return from Babylon.
John W. Ritenbaugh
Elijah and John the Baptist
Other Forerunner Commentary entries containing Mark 1:11: