“Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions.” Ps 51:1
You probably know the story of David, the shepherd boy who became king of Israel. David was the eighth and youngest son of Jesse. (I Sam 16:10-11) According to the Biblical description, David was small, and apparently not as handsome as his brothers, for when Samuel was drawn to another brother, God said:
“Look not on his countenance, or the height of his stature; because I have refused him; for the Lord seeth not as man seeth; for man looketh on the outward appearance, but the Lord looketh on the heart.” (I Sam 16:7 KJV).
The appearance that mattered to God was the heart, and David was favored by God because of his heart. David, was, however, “ruddy….and goodly to look to,” according to I Sam 16:12, and, even though he was young, was the one whom God had chosen to be the next king of Israel.
David faced many challenges before he became king, but relied on the Lord for his strength and grew in faith throughout these experiences. Once he became king, however, he gave in to his sin nature and committed adultery with the beautiful Bathsheba, and then had her husband, Uriah, murdered to cover it up.
The King of Israel murdered a man–one of his own soldiers, in fact. Does that shock you? Actually, none of the patriarchs in the Bible were without sin, as are none of us. Abraham lied about his wife being his sister–twice–to protect himself. Noah got drunk after the flood, and was exposed to his son, Ham. Moses murdered an Egyptian and ran away to Midian. Paul persecuted, jailed, and may have been responsible for many deaths of early Christians before he was converted. David’s sin, then, should not shock us. “For all have sinned and fall short of the glory of God.” Rom 3:23 KJV.
Does God forgive a sin like murder? Yes, God forgives even murder, if the murderer sincerely repents. Perhaps David thought he had made things right with his adultery by seeing that Uriah died on the battlefield and marrying Bathsheba. But several months later, Bathsheba gave birth to their son.
Then the prophet Nathan confronted David and made him realize the depth of his sin, and David repented—deeply–and cried out to the Lord,
“Wash me thoroughly from mine iniquity, and cleanse me from my sin. For I acknowledge my transgressions: and my sin is ever before me. Against thee and thee only have I sinned, and done this evil in thy sight; that thou mightiest be justified when thou speakest, and be clear when thou judgest.” Psalm 51: 2-4
David realized that his sin was more than a single slip-up. His lust and coveting of another man’s wife was caused by a rebellious spirit in him– what David acknowledged as his “transgressions.” The word, “transgression” has been translated from the word, “pesha,” and may be defined as a willful, planned act against a moral code of behavior. Christianity.com defines transgression as: “presumptuous sin. To transgress is to disobey intentionally.” David knew what he was doing was against God’s moral code of behavior, and he did it anyway. He was God’s anointed one and he behaved with a spirit of disobedience!

But, when David deeply repented, his heart was set right with God again. Only the Holy Spirit can bring about this complete change of heart. Study the words of David’s prayer:
“Create in me a clean heart, O God; and renew a right spirit within me,” (Ps 51:10)
In this passage, David was praying for the Holy Spirit to replace his rebellious spirit and give him a new heart. This is real repentance. It is a visible change from the inside out.
David also knew that not repenting of this sin would lead to further separation from God and he prayed,
“Cast me not away from thy presence, and take not thy Holy Spirit from me.” (Ps 51:11)
True repentance involves not just a change of heart, but also a change of behavior in keeping with God’s ordinances. David knew the path that he should follow in the future to prove his true repentance and his change of heart would be demonstrated by the way he lived and influenced others:
“Then will I teach transgressors thy ways and sinners shall be converted unto Thee.” (Ps 51: 13)
Oh, that we might all have a heart like David when he repented; a heart that cried out to the Lord for the right spirit—the Holy Spirit—to cleanse and renew and empower us to live in obedience and to lead other to do the same!
Isn’t that what Jesus commanded the first disciples and every Christian after that—
“Go ye, therefore, into all the world and make disciples of all nations, baptizing them in the name of the Father, and the Son, and the Holy Ghost, teaching them to observe all that I have commanded you.” (Matt 28: 19-20).