Back in my sermon-making days I approached some Sunday mornings feeling like a lowly worm. During the week before, I had not been the best husband, father, or friend. I felt that before God could use me again I had to establish a track record of right living. So I vowed to get through the sermon as best I could and try to live better the coming week.
That was not the right approach. In Galatians 3 it’s said that God continually supplies us with His Spirit and works powerfully through us as a free gift—not because we’ve done anything or could do anything to deserve it.
Abraham’s life demonstrates this. At times he failed as a husband. For example, he twice put Sarah’s life in jeopardy by lying to save his own skin (Genesis 12:10–20; 20:1–18). Yet his faith “was credited to him as righteousness” (Galatians 3:6). Abraham put himself in God’s hands despite his frequent failures, and God used him to bring salvation to the world through his lineage.
There’s no justification for behaving badly. Jesus has asked us to follow Him in obedience, and He supplies the means to do so. A hard, unrepentant heart will always hinder His purposes for us, but His ability to use us doesn’t depend on a lengthy pattern of good behavior. It’s based solely on God’s willingness to work through us as we are: saved and growing by grace. You don’t have to work for His grace—it’s free.
Source: Our Daily Breat