"I have forgiven in the sight of Christ for your sake, in order that Satan might not outwit us. For we are not unaware of his schemes (2 Corinthians 2:10-11 NIV)."
One thing becomes clear when we study scripture: Satan gains an advantage when we harbor unforgiveness in our hearts. Satan gains an advantage that he can and will use against us.
We will experience this as torture to some extent and in some way: "In anger his master turned him over to the jailers to be tortured, until he should pay back all he owed. This is how my heavenly Father will treat each of you unless you forgive your brother from your heart (Matthew 18:34-35 NIV)."
The Bible explains how this comes about.
Forgiveness is not just an idea we have to accept; it's not an intellectual concept that simply can be embraced. You must forgive others "from your heart." And the sooner, the better. When we don't comply fully with what God requires, Satan gains power.
Scripture is clear on this point: "In your anger do not sin": Do not let the sun go down while you are still angry, and do not give the devil a foothold (Ephesians 4:26-27 NIV)." A "foothold" means that the devil can create emotional and/or physical distress in a variety of ways. And at times of his choosing. The devil's purpose, in all that he does, is "to steal, and to kill, and to destroy (John 10:10 NKJV)."
The direct and indirect consequences of unforgiveness are all too common. They include anxiety attacks, depression, digestive problems, headaches and the list goes on. Whenever we give advantage to Satan, expect that Satan will use that power however and whenever he believes he can do the most damage.
But it doesn't have to be this way. We can avoid being defeated by practicing forgiveness with every thought. The more often we do this, the easier it becomes.
When you do find yourself nursing a grudge, confess the sin to God right away. Forgive. Then pray for the person you are angry at. This can be thought of as taking back ground that you have given to the devil in battle.
We are all responsible for how we think. We all bear the consequencesgood and badthat result from our thinking. Our circumstances cannot be used as an excuse to absolve us of this responsibility.
And no amount of therapy will in any way change this stark reality of life.