The LORD said to Cain, “Why are you angry, and why has your face fallen? If you do well, will you not be accepted?” Genesis 4:6-7
Cain believed in God. He believed that the good things in his life were gifts from God’s hand, but he did not listen to what God said and he did not trust what God had promised.
This comes out clearly when God speaks directly to Cain. He had an open invitation to come to God in the way God had appointed. “Cain, you too can be accepted. You too can be commended as righteous. But you must come to Me in the way that I have revealed, and that is on the basis of a life that is laid down as a sacrifice for you.”
This is the first time the word sin is used in the Bible: “And if you do not do well, sin is crouching at the door” (Gen. 4:7). What is sin? “Cain, you light a fire at night to keep wild animals away. Sin is like a wild animal that can destroy you, and if you will not believe what God has revealed and trust what God has promised, sin will overpower you.”
Cain is the father of those who claim to have faith but do not believe what God has revealed. You have, no doubt, met people like this. They will talk a great deal about God and about faith, but they will not listen to Scripture. But faith listens to what God has said. It is formed and fed by the Word of God.
Ask the Lord to save you from the self-will that resists what He has revealed, and help you to grow in the faith that listens to and is shaped by His Word.