Daily we need to fight to believe the gospel while fighting to disbelieve the false promises that sin offers. For those who have trusted in the work of Christ for their salvation, we are new creations, our identity in Christ, and "all the promises of God find their Yes in him. That is why it is through him that we utter our Amen to God for his glory." (2 Corinthians 1:20)
For Gospel Homework, we need to look at in depth what the promises that sin seem to be offering (that is, what need/want of ours are we thinking that the particular sin meets) and combat it with the truth of what Christ offers us in Him. This exercise helps us begin to develop the practice of identifying the promises of sin against the promises of Christ. Here are some examples:
Sexual Lust: The Fight for True Intimacy
Instead of trusting sexual lust for intimacy, trust God to true intimacy: "Blessed are the pure in heart, for they shall see God" (Matthew 5:8). When you are tempted to lust, turn to God's promise for true intimacy, to see God and be ravished with Him in Jesus.
Lust says: "Long for what you cannot have and you will be satisfied."
The gospel says: "Rejoice in what you do have, in Jesus, and you will truly be satisfied."
Vanity: The Fight for True Worthy
Instead of relying on vanity for worthy, consider the beauty of God: "What we will be has not yet appeared; but we know that when he appears we shall be like him, because we shall see him as he is" (1 John 3:2). When you are tempted to find your worth in your appearance, turn to God's beauty and rest in the beauty you have in Him.
Vanity says: "Perform beautifully and you will have worth."
The gospel says: "Jesus performed beautifully for you; therefore, you have never-ending worth."
Pride: The Fight for True Confidence
Instead of trusting in compliments for confidence, believe that your sufficiency comes from God: "Such is the confidence that we have through Christ toward God. Not that we are sufficient in ourselves to claim anything as coming from us, but our sufficiency is from God, who has made us sufficient" (2 Corinthians 3:4-6).
Pride says: "Find and cherish compliments and then you will be confident."
The gospel says: "Your confidence comes, not from your sufficiency, but from God who has made you sufficient in Jesus."
Anger: The Fight for God's Way
Instead of getting angry to get your way (protesting not getting your way), put your trust in the Lord's way: "Be angry, and do not sin; ponder in your own hearts on your beds, and be silent. Offer right sacrifices, and put your trust in the Lord" (Psalm 4:4-5).
Anger says: "If I control my circumstances (and I have a right to) then I will get the best outcome. If I can't control my circumstances, then I have the right to get mad."
The gospel says: "Because Jesus is Lord, He has the right to control my circumstances. Therefore, I will get the best outcome by trusting Him. Put your trust in the Lord, not in controlling your circumstances."
Make this a regular routine in your life for all sins. Line up the promise of sin against the promise of the gospel and see the vast differences between the two. Look for God's grace toward you in these promises. Memorize them. Use them as you battle temptation. Meditate on them throughout your day. But above all, believe the promises in the gospel and encourage others to do so as well.
*Adapted from Gospel Centered Discipleship by Jonathan K. Dodson