JESUS was sent here on earth because there were several missions that needed to be accomplished. JESUS, being perfect and without sin, was the most sacred and holiest of sacrifices, the only sacrifice suitable for the mantle that was laid on him. This was the plan all along to defeat the evil one and sin all together.

Additionally, JESUS was sent to preach the coming of the kingdom of GOD and to pick the twelve (later becoming eleven) who would continue to perform his work on earth, spreading the good news.