"For we maintain that a man is justified by faith apart from works of the Law." Romans 3:28"You see that a man is justified by works and not by faith alone." James 2:24"You have been severed from Christ, you who are seeking to be justified by law; you have fallen from grace." Galatians 5:4
This is the differentiation, brothers and sisters in Christ! Do you see the difference between these verses? Do you understand the difference? A man is not justified by good deeds. A man is not justified by works of the Law. A man is not justified by the Law. A man is justified by faith and by works of faith (faith in action; living faith)—together! Inseparable! "You see that faith was working with his works, and as a result of the works, faith was perfected/completed" (James 2:22).
An illustration I am fond of using to demonstrate this reality is this: Imagine you are hanging from something high up and the fall will hurt you severely. I come beneath you and tell you, "Let go and I'll catch you." It does not matter how much you believe that I will catch you if you do not let go. Your belief in my catching you is useless, worthless, dead, and in vain at that point. The moment you release your grip, your action completes and perfects your belief. Every instance of faith has a corresponding action that must go hand-in-hand with it in order to complete it. If you believe that a chair will support your weight when you sit in it, you actually have to sit in the chair to prove your faith true.
If you do things merely to get right with God and try to earn His favour, then you are engaging in legalism. Nothing you do will ever earn you favour with God and set your right with Him. You repent because God commands and demands you to repent. You obey because God commands and demands you to obey. You do not "repent" and "obey" in order to get right with God and earn favour from Him. If that is your thinking, then you are already damned to an eternity in Hell. You are saved by the merits of Christ alone and by trusting completely and wholeheartedly in what He has done! He has done it all. He was the only one able to please His Father by doing everything right, having never committed sin. He was the perfect sacrifice, being offered on our behalf.
If you do not accept what Christ did, trusting in His life, work, and merit alone, then you are doomed to spend eternity in Hell. Nothing you do, no matter how good you might attempt to be, will ever earn you favour with God and put you in right standing with Him. That does not mean that there are not things that you are still required to do (such as repenting, obeying, and striving to live a life of holiness), but that by doing such things you can never and will never earn God's favour or be in right standing before Him. You are only seen spotless and clean when God looks at you and sees Christ.
Professing Christians who think that all they have to do is "have faith," and that they do not have to do anything else (repent, obey, be holy, etc.) are merely deceiving themselves. They would benefit greatly from reading the entire New Testament and taking note of how many commands are given to the Christian. The New Testament paints a certain picture of what a genuine born-again believer actually looks like, and if you do not measure up, then you are nothing more than a false convert! You might not measure up because you are a babe in Christ, but if you have supposedly been a Christian for 10, 20, 30, 50 years, you are not a "babe" in Christ, but a false convert! Just as it is impossible to remain a physical baby for years, or even your entire life, so too is it impossible to remain a spiritual baby for years, or even your entire life.