All the same
You are no different from everybody else in the world. The devil will tell you your sins are worse, and your mistakes are unique. That nobody else has ever had those terrible thoughts, but friend your struggles are the same as everybody else’s. Your critical thoughts about others or about sex have all been thought before, and God knew all of this before He chose you.
God never looks at people as failures, only learners. God uses failure to reveal Himself as a God of steadfast love. How else can you reveal yourself to your wife as a forgiving, loving, kind, patient person until she disappoints you, annoys you, or opposes you? You can't. This is why the angels don't preach. They can't sing the song of the redeemed. But we can -we know what it is like to be forgiven.
Through our failure, God is teaching us of His steadfast love. He is not saying we should fail or try to fail but He knows we will. Think of the story of a woman caught in adultery. What amazes you the failure of the lady? No the beauty of Jesus!
In the parable of the two debtors, one man owed 50 dollars to another man who owed 5 million dollars to a third man. The third man forgave the debt of 5 million but the forgiven man still went out and demanded the 50 dollars from the man who owed him 50. Jesus states that He expected the behaviour of the 5 million dollar debtor, to be changed by the love and compassion that he had been shown. In the same way, God shows steadfast love and forgiveness to us so it will produce the same characteristic in us. If we are not able to rejoice and receive his full forgiveness and release from guilt, we don’t become people of graciousness and mercy towards others.
Friend, God uses our failures to demonstrate his continuing heartfelt grace and love toward us. To learn that His mercy never ends and never fails because His mercies are new every morning!