Sin is bad. If you read the Bible, that has to be a given. God forgives sin when people truly repent. Again, if you read the Bible, that also has to be a given. Yet even forgiven sin has consequences in life. Take this passage concerning Rehoboam. He secured his rule in the Southern Kingdom of Judah and then turned aside from following the Lord. God raised up Egypt and its pharaoh, Shishak, to overrun Judah. The king and the people repent when they hear this was because of their unfaithfulness. Then there is this response:
When the Lord saw that they had submitted, the Lord’s word came to Shemaiah: Since they have submitted, I won’t destroy them. I will deliver them in a little while, and I won’t use Shishak to pour out my anger against Jerusalem. Nevertheless, they will be subject to him so that they learn the difference between serving me and serving other nations.
Notice, the Lord forgives, but there are still consequences to the sin Rehoboam and his leaders committed. Because they served other gods they will now understand with first-hand experience what it is like to live under other nations and their gods.
God has unconditional love and is very quick to forgive when we truly repent. Yet it is important to remember that even when our sins are forgiven because we did repent–turning our lives around completely and turning our backs to the sin (rather than just feeling bad or guilty for the sin)–there are still real world consequences for our sins. Those do not get wiped out so easily.
This is also a good reminder that while God forgives, he never forgets.
The first foundational principle in my theology is this: God is not dumb. He will not be fooled by us saying we are sorry or asking forgiveness for some sin without truly being repentant. Neither will he keep from instructing us, in ways in which we can understand, so that we will follow him more fully and completely. This instance with Rehoboam is a good example–he followed other gods, now he can be subject to the nations who have those gods. Rehoboam was truly repentant, but God taught him, and the whole nation, what it was like to be under the authority of the false gods they had worshiped. This was to help them understand the need for faithfulness to the Lord in the future.
Our sins may be forgiven in this life, but they still have consequences. The only way to avoid the consequences is to avoid the sin.