Jesus' baptism in the bible is something that we can be very certain of. As with a few other passages in the bible, Jesus' baptism is extremely embarrassing for the Gospel writers. When someone is trying to frame someone as the Son of God, they do not want to imply that this person has sinned and therefore needs to be cleansed - exactly what a baptism was. It should also be noted that Jesus did not have the same baptism to what many people currently think of. Whilst we don't know his exact age, he was definitely sufficiently matured to have consented to his baptism instead of being baptised at his parents' orders.
John the Baptist obviously and openly believed in apocalypticism, this can be seen in Bible passages such as Luke 3:7-9 and Matthew 3:10 where there is obvious dualistic imagery of the tree "that does not bear good fruit" and those that do. Jesus was baptised by John the Baptist - we know this for certain because of the embarrassment this would have caused for the Gospel writers and so this wasn't added in. It also follows that Jesus would have consented to John the Baptist baptising him given the age he was at the time of his baptism; as this is the case, Jesus must have agreed with the message that John the Baptist was preaching. We also know that apocalyptic views were widely held in the Early Church. Since John the Baptist was not a member of the Early Church, Jesus must have been an apocalyptic.
P1 John the Baptist believed in apocalypticism P2 The Early Christian Church held apocalyptic views P3 John the Baptist was not a member of the Early Christian Church C Jesus must have been an apocalyptic prophet in order to link the two