"So David said to Nathan, "I have sinned against the LORD." And Nathan said to David, "The LORD also has put away your sin; you shall not die. However, because by this deed you have given great occasion to the enemies of the LORD to blaspheme, the child also who is born to you shall surely die."
2 Samuel 12:13-14 (NKJV)
Secondly, believing we must forgive and forget is dangerous because it is IRRESPONSIBLE! We can wrongly think that because God has forgotten our sin we must be off the hook when it comes to any consequences of that sin. Hence, a convicted murderer could repent of all his sins and receive forgiveness of his sin of murder. Then he may expect God to miraculously intervene so he does not have to spend any time in jail but be restored to a normal life. Imagine the prisoner’s shock when he learns he has been given a double life sentence without parole. As time goes by he could become hurt, bitter and angry at God for not keeping His word.
When God forgives us he stops treating us as our sin requires (that is, we have restored relationship to God). However, if there are seeds of negative consequences already sown, they will be reaped. This is clearly seen in King David’s life. When the prophet Nathan confronted David with his sins of Adultery and murder he said that God had "put away" his sin but there would still be negative consequences: his baby, the product of that adultery, would die and there would be ongoing problems with his children (which later surface in Amnon’s incest and Absolom’s rebellion).
Was David forgiven? Yes! Did he expect God to take away all negative consequences of his sins? No! But, in the midst of enduring the painful consequences of his sin, he experience renewed relationship with God and supernatural joy in His presence (Psalm 51:11-12). The more damaging our sin is to the testimony we have as a Christian, the more consequences we’ll have to endure even after we have received full forgiveness from God. But the most important thing is that our relationship with God will be fully restored and we’ll experience His love, peace and joy.
When we sin there's a seed of a weed that is sown,
That continues to grow even when forgiveness is known.
It may damage our garden but one thing it won't do
Is break our relationship with the gardener too.
"Father, it's sobering to realize that sins I commit can have a dramatic effect on others. Help me to walk in true godly fear so that I live more and more uprightly, not committing sins that will hurt others. Also, help me to realize that I may be seeing consequences of past sins that have been forgiven. This is a natural outworking of the law of sowing and reaping but it does not mean my relationship with You is broken. Praise You Lord for your amazing grace and mercy lavished upon me.Amen!