"I am crucified with Christ: nevertheless I live…" (Galatians 2:20).
"If any man be in Christ, he is a new creature: old things are passed away; behold, all things are become new" (2 Corinthians 5:17).
You may say, "I know I'm in Christ by faith. I realize I'm a new creature, but I still struggle terribly with a habit. It makes me so discouraged." Satan would love to convince you that God has given up on you. He wants you to think God sees you as dirty, filthy with sin. But it's all a lie. What you're experiencing is the flesh battling against the Spirit in you. This battle is common to all believers. And while you're in the midst of it, Satan wants to convince you that the "old man" is still in control.
No matter what your condition, God does not waver in his love for you. He never stopped loving Adam's race, in spite of all its wickedness, idolatry and lustful ways. He preserved them throughout history to the last days, when he stepped in with his rescue plan. Through the cross, it was possible that all of Adam's race could be reconciled.
You have to know that your standing with God is based on one thing: you are victorious because of the cross. This victory doesn't come through any good thing you do. As Paul says, "They that are in the flesh cannot please God" (Romans 8:8). Our victory comes solely through repentance, faith, belief, trust in God's care for us. And our part is to stand firmly on the position he has graciously given us in Christ. His Word assures us, "You may fail at times. But when I look at you, I see only my Son, Jesus. You're going to come through this battle victorious, with no guilt or condemnation."