If you’ve been around American evangelicalism at all, you might have picked up the idea that God saved you in order to put you to work for Him. Justification is that glorious moment of favor that God gives to those who are for the first time believing in Christ, but it quickly fades into a life of hard work, moral improvement, and careful discipline in spiritual matters. Sound like the Christianity you know?
If so, I’m so happy to tell you this: you don’t know Christianity. Here’s the secret to seeking the joy that God intends for His kids… well, let me give the mic to a maestro of grace:
From Michael Horton’s The Christian Faith,
As John Murray helpfully explains, progressive sanctification depends not only on justification but on God’s once-and-for-all act of claiming us as saints. For many Christians, the change in subject from justification to sanctification roughly corresponds to God’s work for us and our work for God, respectively. The result of this assumption, however, is that for a brief moment at the beginning of the Christian life the focus was on Christ and his blessing of justification that was received through faith alone—itself, in fact, a gift of God. But then the rest of our life is a matter of striving for moral improvement. “Having begun by the Spirit,” Paul asked the Galatians, “are you now being perfected by the flesh?” Sanctification, like justification, has its source not in the “works of the law” but in “hearing with faith” (Gal 3:3 – 5). 
Were you saved by grace through faith? You are. Striving for moral improvement as a matter of willpower and personal commitment will either land you in the hospital, or you’ll quit Christianity (though you’ll have never actually internalized the real grace of God), or if you can pull it off and become a moral person, you’ll have something to boast in, and you’ve become a nasty little canker on the tongue of the church.
No. No, no, no. Our only strength and hope in the Christian life is to look to Jesus – learn Him, be filled with Him, seek Him in all things. And friends, for heaven’s sake, don’t run from God when you’ve sinned… run to Him.
This blog will re-visit this subject frequently. There is much need in the Christian community for these reminders of grace, for the constant removal of the chains of moralism. Be free[d] in Christ!
Thanks for reading,
 Michael Horton, The Christian Life (Grand Rapids: Zondervan, 2011), 650-1.