Origin of the name Jesus:

Derived from the Ecclesiastic Late Latin Iesus, which is from the Ecclesiastic Greek Iēsous, a name derived from the Hebrew yēshū'a, a contraction of yehōshū'a (help of Jehovah, God is salvation). The name, an equivalent of Joshua, is bestowed in honor of Jesus Christ (c. 4 B.C. - c. A.D. 29), the founder of the Christian religion and son of God and the Virgin Mary, regarded by Christians to be the promised Messiah. Unlike most Christians, who decline to use the name Jesus out of respect, Christians in the Spanish-speaking world commonly bestow it to bring the bearer under the special protection of the son of God.

From A World of Baby Names by Teresa Norman.