Everything with God comes down to the same thing–the heart. For example, you can tithe, but if you do it grudgingly, it doesn’t count in His eyes (2 Corinthians 9:7). You can prophesy or be a great preacher, but if you are harsh and unkind to others, it doesn’t count for anything (1 Corinthians 13:1-3).
So, when it comes to forgiveness, it’s the same thing. If you plan a sin with the idea that you can go to God and get forgiven and be in the clear, you’re missing it. Only a truly repentant heart receives forgiveness.
The bottom line is that sin is serious business. Time with God, reading His Word and endeavoring to hear His voice will develop a heart that fears (respects and reverences) Him and His commands. It will keep you from the desire to sin and deliver you from temptation.
If you have committed a sin that you planned, but feel remorse and are repentant, you can be assured of God’s forgiveness through Jesus Christ.