Psalm 51:4-6 meaning

David continues his psalm of penitence (sorrow, repentance) after being rebuked for his sins: adultery with Bathsheba and arranging the death of her husband Uriah, as described in 2 Samuel 11:1 - 12:25. 

David further acknowledges that all sin is, ultimately, against God.

Against You, You only, I have sinned
And done what is evil in Your sight,
So that You are justified
when You speak
And blameless when You judge (v 4). 

When reading the context in 2 Samuel 11 and 12 and we might wonder how David could make the statement Against You, You only, I have sinned. 

David clearly sinned against Bathsheba, Uriah, and even the people of Israel, to whom he was king. Nathan the prophet confronted David in 2 Samuel 12:9, saying, 

"Why have you despised the word of the Lord by doing evil in His sight? You have struck down Uriah the Hittite with the sword, have taken his wife to be your wife, and have killed him with the sword of the sons of Ammon." 

David saw that what he had done was sin, and sin at the deepest level was against God: Against You, You only, I have sinned.

In this sense, the Pharisees were correct when they reasoned within their hearts: "who can forgive sins but God alone?" (Mark 2:6-7) as Jesus forgave the paralytic of his sins (Mark 2:5). Ironically, their own sin blinded them from recognizing that Jesus was God. Because all sin is ultimately against God, only God has the power to fully blot out our sin.

As we see in this psalm, David was wrestling with the root of sin in his own heart, so he concludes that any sin against man was first and foremost against God. All sin is evil in God's sight. We can consider some sins worse than others, and it is certainly true that the earthly consequences can vary depending on the nature of the sin. However, compared to the light of the righteousness of the Holy God, all sin is darkness. We can see this in 1 John: "This is the message we have heard from Him and announce to you, that God is light, and in Him there is no darkness at all" (1 John 1:5). 

When David says Against You, You only, I have sinned, he has become aware that the greatest consequence of sin is in the fellowship we have with God the Father. As we read in 1 John, if we walk in the darkness (sin), our fellowship with the Father is broken. Sin is more than a transgression against the law, it is evil in God's sight. 

This does not lessen the seriousness nor consequence of one person's sin against self or another. It is instead a dramatic refocusing of a self-centric view on sin. This Other-centric outlook—seen from God's point of view—enables us to perceive and grapple with the much greater and detrimental outcome that the reality of sin imposes. Sin, iniquity, transgression, disobedience ultimately and most profoundly cause a rift between the Sovereign Righteous Creator God and the beings whom God created in His own image. In the smallest to the largest matters, therefore, sin involving oneself or directed against another is in truth most inescapably a sin against God.

When our fellowship with God is broken, our entire life is affected. Broken fellowship with God inevitably leads to broken fellowship with other people. In David's case, that included a consequence of death. 

The beginning of the road back to restoring fellowship with God, of walking in the light and having fellowship with both God and with man, is agreeing with God that we have sinned. The phrase So that You are justified when You speak And blameless when You judge is a confession that God's ways are the right, or justified ways. God's ways, not our ways. There is no rationalization here. 

God is blameless, and when He judges He is right because His ways are consistent with His (good) design of all creation. When we live apart from, and twist God's (good) design, we create separation from His (good) design—which is death (death being separation). One of those separations is a separation of fellowship. Confession (of what is true) is a means to restore fellowship. 

Confession or repentance begins when we agree with God that we have sinned against Him. It is important for us to realize that we come to God on His terms. We can (and often do) try to justify our sin, to rationalize our behavior. Or perhaps we tell ourselves that God is not justified to consider some action or attitude as a sin. But God is always justified in all He says. 

We can also deceive ourselves as we look at our world. Perhaps things that society might have considered a sin at one time is now "normalized." Some people consider that humankind is in the process of evolving or being enlightened, and consider embracing sin as "progress." God, however, does not change. As Hebrews 13:8 says, "Jesus Christ is the same yesterday and today and forever." 

This may seem unsettling as the world around us seems to change every day. But our unchanging God and His law is a steady foundation upon which we can build the "house" of our lives (Matthew 7:24). God is infinite and all things are in Him. John 1:3 declares, "All things come into being through Him, and apart from Him nothing came into being that has come into being." 

Those who have believed in Jesus are gifted to have a living, dynamic relationship with Christ. All believers are adopted into God's family, and have God as their unchanging inheritance. A believer's relationship (as a child of God) is permanent, and unchanging (Romans 11:29). But just like human relationships, the ongoing personal fellowship is not just static. Our relational fellowship is dynamic, and has the opportunity to grow and flourish. As David confesses to God, he is restoring fellowship, and restarting the growth in that dynamic relationship. 

When New Testament believers have faith in Jesus we are given a new nature:

 "Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come."
(2 Corinthians 5:17)

This is good news, because we need to be given a new nature. This is because the nature we are born with is fallen:

Behold, I was brought forth in iniquity,
And in sin my mother conceived me (v 5). 

This is a rather startling, bold statement. When we hold a newborn baby, one of the words that comes to mind is the word innocent. 

It is common for Christian traditions to speak of an "age of innocence." That is, before we reach a certain age, we are not responsible for our acts that could be considered a sin. Therefore, if we die before that age, we will live eternally with Jesus Christ. There are a number of passages that support this notion, including one that involves King David (2 Samuel 12:23). 

David is not speaking directly to this issue, but rather to the reality that all humans are born into sin. Romans says, 

"Therefore, just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned—"
(Romans 5:12)

The "one man" referred to is Adam; it was through Adam that humanity fell. Accordingly, we enter the world under the predicament of sin. 

Romans 3:23 declares that "all have sinned and fall short of the glory of God." Paul states in Romans 6:23, "For the wages of sin is death." 

This is where David is headed when he says I was brought forth in iniquity, and in sin my mother conceived me." There is also some Jewish tradition that holds that this verse indicates that David was an illegitimate son of Jesse, which is part of the reason he was not brought before Samuel by his father (1 Samuel 16:11). This could be the case—it would fit the general pattern of God placing broken people who have been redeemed into the lineage of Christ (such as Rahab and Tamar). But in any event, this verse applies to all humans in Adam's lineage; we all inherited Adam's fallenness. 

David now turns to speak of God's light shining into his soul,

Behold, You desire truth in the innermost being,
And in the hidden part You will make me know wisdom (v 6).

David has recognized the sinfulness of his own heart and now begins to try and come to terms with how he can come to God for a solution to his own condition: You desire truth in the innermost being. He realizes the deceitfulness of his own heart and that God must search his innermost being. David was likely rationalizing his sin. Once Nathan brought light to his soul he recognized that what he needed was truth. Through Nathan, God brought the truth that he had sinned. 

The truth David recognized needed to be implanted in his innermost being. This expresses a willingness to have a total vulnerability and intimacy with God. Scripture indicates that God knows our inner thoughts even better than we do (Hebrews 4:12). That David expresses that God has a desire for truth in the innermost being infers that God has knowledge of what we believe in our innermost being. 

This truth in the innermost being leads to gaining wisdom. The very definition of wisdom is to live life constructively. Thus, gaining truth in the innermost being becomes our outer expression of life, in actions and thoughts. 

This image of truth springing forth as wisdom brings to mind the conversation of Jesus and the woman of Samaria at Jacob's Well. There Jesus painted a picture of a well of living water springing forth from the soul:

"but whoever drinks of the water that I will give him shall never thirst; but the water that I will give him will become in him a well of water springing up to eternal life."
(John 4:14)

David had experienced God in many ways, had been called by Him, protected by Him, and blessed by Him. So in his own mind he might have questioned "How could I do these evil things against God?" Paul gives an insight to this very question in Galatians 5:19, "Now the deeds of the flesh (sinful nature) are evident." The "deeds," "transgressions," and "sins" spring from the sin (in which) my mother conceived me. David received forgiveness when Nathan says to David in 2 Samuel 12:13, "The Lord also has taken away your sin; you shall not die." But it appears that David realized he also needed truth in his innermost being that he might have wisdom and live according to God's design, rather than the twisted ways of his fallen nature. 

King David had ignored these demands in his personal behavior. Likewise, he had abandoned the moral and ethical responsibilities to the people that Israel's covenant with God required of a reigning monarch. David understands that God's desire (Hebrew "chaphets") is not something as trivial as mere wishful thinking or a sullen pout on the Lord's part. Embracing and carrying out God's desire—endeavoring to bring delight to the Lord—is integral to an authentic, loving relationship with the Creator. 

Lacking faithful pursuit of the righteous standards of God, all the external and visible trappings of the king's moral authority and legitimate claim to governing under God's covenant were patently counterfeit. Consequently, truth was no longer the main characteristic of David's innermost being (Hebrew "tuchah").

From what David has said leading up to this statement and where he is going in later words, it appears he is confessing that sin is an issue of the heart. This is confirmed by other parts of the scripture:

• Jeremiah, the prophet, says "The heart is more deceitful than all else and is desperately sick" (Jeremiah 17:9). 
• Jesus says in Mark 7:21-23, "For from within, out of the heart of men, proceed the evil thoughts, fornications, thefts, murders, adulteries, deeds of coveting and wickedness, as well as deceit, sensuality, envy, slander, pride and foolishness. All these evil things proceed from within and defile the man." 

David poetically repeats the idea that having the light of truth shine in his innermost being leads to wisdom: And in the hidden part You will make me know wisdom. 

The result of truth taking root deep within the soul is the fruit of wisdom. Wisdom is of God. James writes "But the wisdom from above is first pure, then peaceable, gentle, reasonable, full of mercy and good fruits, unwavering, without hypocrisy" (James 4:17).

David has become aware that his confession will lead to God's work deep within his soul. The result is that truth and wisdom will replace the deceit and wickedness in his innermost being. In fact, it will change his perspective, worldview, and attitude. David's perspective will begin to align with God's, and lead him to live consistent with God's design—which is to say to live with wisdom. 

When we walk in the reality of being a new creation in Christ, which is a New Testament application of David's prayer, we then are able to see God through the truth and wisdom of God. Truth in the innermost being and wisdom in the hidden part will allow us to accomplish the admonition Paul gives to his disciples in his letter to the Philippians:

"Have this attitude in yourselves which was also in Christ Jesus, who, although He existed in the form of God, did not regard equality with God a thing to be grasped, but emptied Himself, taking the for a bond-servant, and being made in the likeness of men. Being found in appearance as a man, He humbled Himself by becoming obedient to the point of death, even death on a cross."
(Philippians 2:5-8)