Proverbs 21:2 says. "Every way of a man is right in his own eyes; but Jehovah weighs the heart." When we don't intentionally seek God, we end up justifying our own actions. David justified not going to war in the Old Testament, just as many times we justify not doing spiritual warfare under the New Covenant. God wants to show us the things we don't see about ourselves. If we cry to God and have a heart that is after Him, He will show us our blind spots so we can repent and turn completely from them.