What does Hebrews 11:4 mean?
This passage focuses on examples of faithful obedience from the Old Testament, to show that God's favor was on those whose trust led to obedience. Abel was the second son of Adam and Eve, after his older brother Cain (Genesis 4:1–2). Both brought sacrifices to God, but Abel's was apparently a more sincere and acceptable sacrifice than Cain's (Genesis 4:3–5). Despite God's reassurances, Cain responded to God's rejection of his sacrifice by murdering his brother and attempting to hide the body (Genesis 4:6–10).This makes Abel an interesting inclusion on this list. The pattern being shown here is that God will bless those who respond to Him in obedience—yet the opening example is the victim of Scripture's first recorded murder! However, this fits perfectly with the purpose of the book of Hebrews. Faith, as defined earlier, is a forward-looking trust that God will make good on His promises, even when that fulfillment is "unseen" to us. Abel obeyed God's commands, in faith, and was accepted by God. As the writer of Hebrews has shown, it is this trusting faith—not ritual actions—which brings God's commendation. Abel's sacrifice didn't cleanse him from sin (Hebrews 10:3–4); his faith in God is what saved him.
Despite suffering a violent end to his earthly life, God worked out everything for Abel's good (Romans 8:28–30), in an eternal sense. Abel was "accepted" by God, while his murderer was not. And, Abel's example of faith is still a potent lesson, despite the fact that he was killed for it.
Interestingly, the next figure mentioned as an example of faith is Enoch, a man who apparently was taken by God before experiencing physical death (Genesis 5:24). The contrast between these two lives is no accident. The writer of Hebrews is specifically pointing out that the circumstances of our earthly lives, even when they seem impossible to understand, are irrelevant to God's plans for us. He can, and will, fulfill His promises out of things unseen.