Jesus came not for the righteous, but for sinners,

Matthew highlights these shaky and shady limbs in the family tree, but God chose them. 

Matthew 1:1-5 "A record of the genealogy of Jesus Christ the son of David, the son of Abraham: Abraham was the father of Isaac, Isaac the father of Jacob, Jacob, the father of Judah and his brothers, Judah the father of Perez and Zerah, whose mother was Tamar, Perez the father of Hezron, Hezron the father of Ram, Ram the father of Amminadab, Amminadab the father of Nahshon, Nahshon the father of Salmon, Salmon the father of Boaz, Boaz, whose mother was Rahab…"

Rahab the… harlot.

Rahab the Helper. Say that with me, Rahab the helper. Good!

Christmas is an invitation to sinners. 

Joshua 2:8-11 - 8 Before the spies lay down for the night, she went up on the roof 9 and said to them, “I know that the Lord has given you this land and that a great fear of you has fallen on us, so that all who live in this country are melting in fear because of you. 10 We have heard how the Lord dried up the water of the Red Sea[a] for you when you came out of Egypt, and what you did to Sihon and Og, the two kings of the Amorites east of the Jordan, whom you completely destroyed.[b] 11 When we heard of it, our hearts melted in fear and everyone’s courage failed because of you, for the Lord your God is God in heaven above and on the earth below.

Joshua 2:12-14 - 12 “Now then, please swear to me by the Lord that you will show kindness to my family, because I have shown kindness to you. Give me a sure sign 13 that you will spare the lives of my father and mother, my brothers and sisters, and all who belong to them—and that you will save us from death.” 14 “Our lives for your lives!” the men assured her. “If you don’t tell what we are doing, we will treat you kindly and faithfully when the Lord gives us the land.”

Joshua 6:22-25 - 22 Joshua said to the two men who had spied out the land, “Go into the prostitute’s house and bring her out and all who belong to her, in accordance with your oath to her.” 23 So the young men who had done the spying went in and brought out Rahab, her father and mother, her brothers and sisters and all who belonged to her. They brought out her entire family and put them in a place outside the camp of Israel. 24 Then they burned the whole city and everything in it, but they put the silver and gold and the articles of bronze and iron into the treasury of the Lord’s house. 25 But Joshua spared Rahab the prostitute, with her family and all who belonged to her, because she hid the men Joshua had sent as spies to Jericho—and she lives among the Israelites to this day.

God saves sinners while they are sinners, not after they get their act together.