Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. 14 Stand firm then, with the belt of truth buckled around your waist,with the breastplate of righteousness in place, 15 and with your feet fitted with the readiness that comes from the gospel of peace. – Ephesians 6:13-15
Christ is the ground of your righteous standing before God, your acceptance before Him. If you are wearing that
breastplate, you can rest secure that your heart, your emotions, are securely guarded and adequately protected against attack. This is perhaps the most frequent ground of attack against Christian faith. Christians often feel they lack assurance….
They feel unworthy of God. They feel they are a failure in the Christian life and that God is certain to reject them, that He is no longer interested in them. They are so aware of their failures and shortcomings. Growth has been so slow. The first joy of faith has faded, and they feel God is angry with them or that He is far off somewhere. There is a constant sense of guilt. Their conscience is always stabbing them, making them unhappy. They feel God blames them. This is simply a satanic attack.
How do you answer an attack like this? You are to remember that you have put on the breastplate of righteousness. In other words, you do not stand on your own merits. You never did. You never had anything worthwhile in yourself to offer to God. You gave all that up when you came to Christ. You quit trying to be good enough to please God. You came on His merits. You came on the ground of His imputed righteousness—that which He gives to you. You began your Christian life like that, and there is no change now. You are still standing before God on that basis.