Shorter Catechism Q. 39

Q. 39. What is the duty which God requireth of man?

A. The duty which God requireth of man, is obedience to his revealed will.


Matthew 28:19–20; Romans 1:5


It’s been a while, but perhaps you remember Q & A 3. “The Scriptures principally teach, what man is to believe concerning God, and what duty God requires of man.” Accordingly, the Shorter Catechism is itself divided into two main sections. The first part had to do with what we are to believe concerning God. So questions 4–38 taught us who God is, who we were created to be and what we have become in our sin, how God has redeemed us by his Son Jesus Christ, and how the Holy Spirit gives us confidence and assurance to live with joy. And, now, the Shorter Catechism begins its second section and puts before us what duty God requires from us.

But that’s the point, isn’t it?

Living the Christian life is a hard work. We are called to do no less than submit all our heart and body to the Lord, to take every thought captive for the Lord, and do all things, whether we eat or drink, or what ever we do, for God’s glory. In fact, it is so hard that the only thing that makes it possible is gratitude.

Let’s imagine we serve God for fear of punishment if we do not obey God. Sadly, this is in fact how many Christians think. They obey God out of fear. But fear can motivate us to obey only so much. Fear, naturally, robs all joy from our heart. But we are just not built to do anything we do not enjoy for long. Sooner or later, fear will degenerate into apathy. When that happens, people who once tried to live in obedience just don’t care anymore. Perhaps you know people like this. Perhaps you have become like this.

Or imagine trying to serve God because we are motivated by what we may gain out of it. But if that is the case, as soon as we see no personal benefit in obedience, we will lose all desire for the Christian life. It’s not just the followers of the health-wealth gospel who live with a crass theology. Every believer who is not rightly motivated to live the Christian life is trying to manipulate God, either to appease him with service or handle him to bless us. Neither motivation is biblical.

Instead, the only motivation that can make living the Christian life joyful is gratitude for what God has done for us in Jesus Christ. So Paul in Romans 1:5 says he wants to bring about “obedience of faith.” He means our faith in Christ (who he is and what he has done) brings about obedience. And it is the risen Lord who conquered our sin and death that calls us to be disciples and to “observe all that [he] has commanded.” In other words, obedience is the fruit of a grateful heart. Christ loved us and gave himself for us. His love for us changes the reason for our obedience. Before, it was to please him or to get something out of him. Now, we want to live for the one who has died for us. We want to love the one who bore our sins on the cross.

It is for that reason why the Shorter Catechism first taught us “what we are to believe concerning God.” Only when we have learned who he is, who we are, and what God has done for us that we live the Christian life with joy. Joyful obedience comes from a grateful heart.

So I have some questions for you.

  1. Are you afraid God will judge you because you are not doing enough? Then you are serving God out of fear, not out of gratitude. Remind yourself that all you do is an answer to his grace.

  2. Are you apathetic or do you just not care about living in obedience to God? Then you have either never understood the gospel, or you need to learn it again and believe it again.

  3. Do you regularly think of Jesus’ death in your place, and his resurrection for you? Start doing so. Only gratitude produces God-pleasing obedience.