And this blood shall be to you for a sign upon the houses where ye are; and when I see the blood, I will pass over you (Ex. 12:13).
If you want to change the way you act, you have to change the way you think. Real change comes from the inside out. What you focus on grows. Legalism is living by rules, which necessitates an emphasis on doing what is right rather than wrong. Your need to be right is so strong that you fail to put your trust in Jesus who makes you righteous. True faith in Jesus’ life giving sacrifice, the shedding of His blood, is the only way to make sinners right in the sight of God.
You can either center your attention on everything you are doing right, as well as wrong, or you can focus on the precious blood of Jesus, the price He paid for you to belong to Him. His love for you far outweighs your efforts to be good, in fact, no one is good, no not one. Jesus is your Passover lamb and like the ancient Israelites who huddled within their houses on the night of their exodus from Egypt you must look at the blood for it is the sign of your salvation. Living by the power of your flesh and trying to do right is an exercise in futility. Living by faith in Jesus Christ and the price He paid for you will give you grace (a supernatural endowment) to fulfill the law.
Fear not because Jesus is the First and the Last. The first redeems the whole. Think about Jesus and His love for you, how He died to set you free from the slavery of sin. Confess His life giving blood over yourself and the truth that He now owns you. By putting Him first in your thoughts, your actions will change, and your feelings will too. You will be able to live right by His grace and not by your efforts, which drain your strength and joy.