I am always struck by the women mentioned in the genealogy of Jesus in Matthew chapter 1. Verses 1 through 17 list the generations from Abraham to Jesus, 42 generations in all, and only 5 women are mentioned.
Knowing that Jesus is the Messiah, we might expect these to be the most righteous and pure women. However, a closer look reminds us that God can use everyone to fulfill His purposes, regardless of their past.
Tamar was the daughter-in-law of Judah. She disguised herself as a prostitute in order to lure Judah to sleep with her so that she could bear a child in Judah's line.
Rahab was the prostitute who helped the Israelite spies escape from Jericho by lowering them out the window.
Ruth was a Moabitess who married an Israelite. After she was widowed, she followed her bitter mother-in-law back to Bethlehem. She gleaned barley in the field (gleanings were leftovers after a crop was harvested and were reserved for the poor and the foreigner).
Bathsheba was the wife of another man when King David summoned her to him. After King David had her husband, Uriah, killed in battle, she become one of his wives.
Each of these women had things in their past that we might tend to judge harshly. Even in the church today, we might feel that these women are not "good" enough to serve or lead. Yet, God, who looks at the heart, not only used these women to fulfill His promise of a Messiah, He also ensured they were remembered by having Matthew include them in the lineage of Jesus!
The fifth woman mentioned is Mary, the mother of Jesus. She stands in stark contrast to the others as she is a young girl, a virgin betrothed to Joseph. When the angel first appears to her, she is afraid, yet she submits to the will of the Lord and says, "I am a servant of the Lord; let it be to me according to your word."
Have you made poor choices in the past? Have you had bad things happen to you that make you feel unworthy? These things don't have to preclude you from serving the Lord or being used for His purposes! Go to Him with an open heart and be willing to submit to His will.