Imagine Abraham, living a life of security in Ur of the Chaldeans, but knowing that God had called him to leave it all for a land he did not know. That would have been costly.

And Abraham is not alone. God calls each of us to obedience that’s costly, like loving our enemies, sharing the gospel, forgiving those who hurt us, and battling sin.

So how did Abraham obey, when it was so costly?

Two Simple Words

God tells us in Hebrews 11:8, “By faith Abraham obeyed when he was called to go out to a place that he was to receive as an inheritance.”

There’s the secret. Abraham obeyed by faith. So what does that mean?

If you were going to travel by bike, that means the bike is how you would travel. The bike is what you would use in order to travel. In the same way, if you were going to obey by faith, that means faith is how you would obey. Faith is how we pursue Christian obedience.

But how does that work?

Trusting God’s Promises

Faith means trusting God’s promises — trusting all that God promises to be to us in Christ Jesus. So if faith means trusting God’s promises, and Abraham obeyed by faith, that means Abraham obeyed by trusting God’s promises.

We can see that this is how God wanted Abraham to obey, by noticing what God says to him. God starts with a command: “Now the Lᴏʀᴅ said to Abram, ‘Go from your country and your kindred and your father’s house to the land that I will show you’” (Genesis 12:1).

But God follows this command with astonishing promises:

“And I will make of you a great nation, and I will bless you and make your name great, so that you will be a blessing. I will bless those who bless you, and him who dishonors you I will curse, and in you all the families of the earth shall be blessed.” (Genesis 12:2–3)

So how did God want Abraham to obey? Not by just focusing on the command. Not by just saying, “I’m supposed to do this. God commands me to do this. This is the right thing to do.” No. God wanted Abraham to obey by faith — by trusting God’s promises. God wanted the worth of his promises to so capture Abraham’s heart so that he wanted to obey.

It’s Not Easy

But that would not have been easy. One reason is because Abraham’s indwelling sin would urge him not to trust God. The other is because God’s promises were future and thus unseen to Abraham.

So, like all of us, Abraham would have needed to pray and ask God to strengthen his faith (Mark 9:24). He would have known that faith comes by prayerfully hearing God’s word (Romans 10:17).

So he would have prayed and set his heart on trusting God’s promises until the Holy Spirit strengthened his faith so he knew and felt — if I obey, God will . . . • make of me a great nation • bless me so I will be a blessing • bless those who bless me and curse those who dishonor me • bless all the peoples of the earth through me (my descendant, the Messiah).

Then, when Abraham trusted all that God would do for him, he would obey —

Sarah, God has told me something wonderful. He promises that if we go to a land he will show us, he will make of us a great nation. He will bless us and make us blessings. And he will bless the whole earth through us. Let's start packing!

Obeying by Faith

Abraham obeyed by faith; by trusting God’s promises. But what’s shocking is that many of us try to obey without trusting God’s promises.

Here’s an example. Most of us are familiar with the command of Colossians 3:23 — whatever you do, work heartily, as for the Lord and not for men. We know that command. We’ve tried to obey that command. But have we obeyed that command by faith? Do we know the promise God attaches to that command to help us obey? If we don’t, then how can we have been obeying by faith?

So what’s the promise? Look at the larger context. “Whatever you do, work heartily, as for the Lord and not for men, knowing that from the Lord you will receive the inheritance as your reward” (Colossians 3:23–24).

Did you notice how we are to obey? It’s by knowing — by trusting — that from the Lord we will receive the inheritance as our reward.

So God does not just want us to work heartily. God wants us to work heartily, because we know and trust his promise that he will mercifully reward our undeserving work with the inheritance of more joy in him forever.

Lifting a Rocket Ship

Imagine a huge rocket ship called Obedience. It’s made to be powered by a fuel called Promises, which is ignited by Faith. So don’t ignore the fuel of the Promises. Don’t try to lift the rocket ship of Obedience by your own power.

Instead, ignite the fuel of the Promises by Faith. And watch Obedience blast off.