Catholics believe that Jesus was both fully God and fully man. Much of the emphasis on Jesus is placed on his divinity, though, and his humanity seems forgotten. His humanity was actually very important to who Jesus was and had a great affect on his mission.
Jesus was the Jewish son of Mary and the adopted son of Joseph. His lineage can be traced back to the great Jewish king David, and grew up living the life of a carpenter's son. He had parents who cared for him and raised him like any other Jewish boy of the time. Jesus probably studied scripture and went to some kind of school as a child, but nothing specific is known about his childhood.
After his baptism, Jesus withdrew to a desert to pray. During that time, "he was hungry," and he faced temptation like we do everyday. He had a choice to do what was right or to do what was easy and temporarily satisfying, and he chose to do what was right, something we do not always do.
If Jesus' teachings were so radical, why were they widely accepted?
There are two parts to this answer: Jesus as a miracle-worker and Jesus as a person. I will focus more on Jesus the person, but the miracles are worth mentioning. Jesus performed innumerable miracles, most of which involved healing those afflicted with incurable diseases. People seeing this were very likely to believe in him and what he said after watching such things. The second part focuses on Jesus' personality. He was a naturally likable man with a tremendous disposition. He was fun to be around and "hang out with." Jesus did not go to large gatherings and weddings just to politick or perform works; he had a good time and reveled with everyone else in a non-sinning sort of way. When Jesus spoke, people listened. He was a great orator who was never at a loss for words. Anytime a question was posed to him, Jesus had a appropriate and intelligent response. His words captivated the masses and gained a following so great that the people Jesus taught "against," the priests, Pharisees, and scribes, were threatened. This fear is what led to Jesus' death.
Jesus' death was a great example of his humanity. He feared his death for a great portion of his adult life, and did not want to go through with it. He even asked, "Father, if you are willing, take this cup away from me; still. not my will but yours be done."(Lk 22:42) Later, after he had been nailed to the cross, Jesus cried out to God asking why He had forsaken him.
Jesus is the best model for us on how to live good lives. Jesus struggled for much of his life, but overcame the struggle better than anyone else ever has. He was faced with cynics, opposition from the powerful, his own burden, and even the devil himself. Yet, Jesus made the correct choice every time. He encountered the sin in his age because he had the same desires, such as lust and hatred, that we have, but managed to handle them better than any of us could ever hope to. If we want to live a coorect life for God, then we should start by watching how Jesus the human lived, and attempt to emulate the man who was best at being a man who ever lived.