What does Matthew 1:25 mean?

This verse completes a statement begun in the previous verse, which highlights Joseph's remarkable faith (Matthew 1:24). While Luke's telling of the birth of Jesus focuses on Mary's experience, Matthew considers the events from Joseph's perspective.

An honorable and God-fearing man in that culture could have quietly ended this betrothal with a clear conscience. He was not obligated to follow through on his commitment to marry a woman found to be pregnant by another man. Joseph, though, decided he was obligated after being told the real story of what was going on by an angel of the Lord in a dream (Matthew 1:19–21). Mary, still a virgin, carried "God with us," the Savior (Matthew 1:22–23).

Joseph obeyed God, likely at the cost of his own reputation—rumors about Jesus' birth seem to have persisted during His ministry (John 8:19; 8:41–42). He also waived his legal rights to avoid responsibility for Mary or her child. Instead of divorcing her or even waiting for the time of betrothal to end, Joseph immediately took Mary home to live with him. Not only would this minimize any scandal, it allowed Joseph to begin his work of providing for his pregnant wife and the child Messiah.

Matthew makes clear in this verse, though, that Joseph did not have sex with Mary until after Jesus was born. The text uses the biblical euphemism for sex "know." Joseph "knew her not." Matthew also does not suggest that Joseph never had sex with Mary, as some traditions teach. They experienced regular marital relations after the birth of Jesus and had several children together in the natural way (Matthew 13:55–57; Mark 3:31–32).

Joseph also showed that he heard and understood God's command through the angel in his dream by naming the baby Jesus. Jesus is derived from the same Hebrew name from which we get "Joshua," and means "Yahweh saves." Yahweh is a Hebrew name for God.