And to whom did He swear that they would not enter His rest, but to those who did not obey? 19 So we see that they could not enter in because of unbelief.
Hebrews 3:18-19

Christianity is unlike every other religion in that every other religion is based on what man does to get to God. Christianity, however, is not based on what man does to get to God but on what God has done to reach down to and save sinners. God has reached down to man via His Son, Jesus Christ, who did everything for us that God requires of us, but that we are incapable of doing. Then Jesus died for us, paying the penalty for all of the wrong deeds we have done, and for our failure to do the good deeds that were required of us. We receive the benefit of what Jesus Christ has done for us by faith—alone.

So why does the writer of the book of Hebrews tell us that the children of Israel did not enter into the Promised Land because they did not obey God? And even more curious is that in the very next verse, he says they did not enter the Promised Land because they did not believe God? Does God require obedience or faith?

The answer is both, and the relationship between faith and obedience is both inseparable and crucial. How?

First, God commands us to believe. So a failure to believe is in itself a failure to obey.

Second, believing God means believing that He is right about everything—enough to obey Him.

God has provided everything we need to be forgiven of our sins, reconciled with Him, and to be intimate with Him. When we experience these things we have entered into His rest. But although He has supplied everything for us to enter that rest, to experience His rest we must obediently believe Him and believe Him enough to obey him.

As the old gospel hymn goes, “Trust and obey, for there’s no other way to be happy in Jesus, but to trust and obey.”