As we consider the history of God’s people in the Old Testament, we do not observe a people who served the Lord faithfully. The people of Israel did not demonstrate their love for God with all their hearts. Even some of the great heroes of Israel manifested the depths of depravity in their lives.
Nevertheless, it is through our careful study of Israel’s past that we find great comfort. With spiritually discerning minds, we have been given the ability to understand the way in which God’s redemption of His people has been displayed throughout history. As such, we possess insight into the unfolding drama of redemption, from the beginning of life itself to the very end when death itself is conquered.
It is for no small reason that God’s record of His people is replete with stories of failure and renewal. For it is in the history of redemption that the patient God of Israel restores His people time after time, demonstrating His enduring love and faithfulness. Despite their lawlessness and rebellion, the people of God in the Old Testament were repeatedly brought to repentance by the kindness of God and were always renewed in their sweet communion with Him. This common theme of restoration is perhaps best illustrated in the life of David who was the son of Jesse, the shepherd of Bethlehem, the defender of the kingdom of God, the king of Israel, the adulterer, the deceiver, and the murderer. In the biblical portrait of David, we observe a man whose heart was broken by his sin and healed by his Lord.
Upon the occasion of David’s anointing, we recall the words of God to Samuel concerning David’s older brother Eliab: “Do not look on his appearance or on the height of his stature, because I have rejected him. For the LORD sees not as man sees: man looks on the outward appearance, but the LORD looks on the heart” (1 Sam. 16:7). The boldness and sheer magnificence of these words demand that we hearken to the words of Samuel when he proclaimed to Saul that “the LORD has sought out a man after his own heart…to be prince over his people” (1 Sam. 13:14). David was a man after God’s own heart, not because the heart of David was pure. Instead, he was a man after God’s own heart precisely because he understood that his heart was not pure, and for that reason he hid the Word of God in his heart so that he might not sin against the Lord and so that he might love the Lord with all his heart.
Regardless of your past, God has a plan for you. Perhaps you think that you have done too much to be used. Compare your life with David. Have you committed the sins that he did? God used David in spite of himself. God can use you too. The Bible says that if you confess your sins, He is faithful and just to restore you to righteousness (1 John 1:9).
If you’ve never taken the first step to salvation, you need to take care of that first. Read what the Bible says:
John 3:14-18 CSB
“Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up,  so that everyone who believes in him may have eternal life.  For God loved the world in this way: He gave his one and only Son, so that everyone who believes in him will not perish but have eternal life.  For God did not send his Son into the world to condemn the world, but to save the world through him.  Anyone who believes in him is not condemned, but anyone who does not believe is already condemned, because he has not believed in the name of the one and only Son of God.
Romans 10:9-10 CSB
If you confess with your mouth, “Jesus is Lord,” and believe in your heart that God raised him from the dead, you will be saved.  One believes with the heart, resulting in righteousness, and one confesses with the mouth, resulting in salvation.