As Reformed believers we can rightly become very excited about discovering the depths of the biblical riches of God's grace. But as a result of wrong thinking about this, many of our churches avoid talking about obedience. One reason is that many have been burned in the past by legalistic churches or another is that they may be afraid of compromising the crucial doctrine of justification through faith alone. Those are good things to avoid but passages like Titus 2:12 teach "us to say “No” to ungodliness and worldly passions, and to live self-controlled, upright and godly lives in this present age." In fact the New Testament is full of divine commands or imperatives. True if taken in the wrong way, these commands could be construed as legalism or justification by works, but when regeneration is understood aright, the renewed heart, where the Spirit is at work, makes these commands part of our inner delight in living for Christ. We obey because the Spirit has united us to Christ and inclined our hearts toward holiness .... not in order to be saved but because we are saved. All obedience needs to be grounded in grace ... that is springs from Christ's work, not something we do in order to deserve Christ's blessing. Our motive for obedience shows whether we understand the gospel or not.
Lets be blunt - the New Testament authors put great emphasis on declaring how regenerate Christians can please God by their obedience.But we must learn to distinguish between justification (on the one hand) and regeneration (on the other). If we think we can maintain our salvation by our obedience then we have it backwards. Our just standing before God has been established by Christ. He has qualified to share in the inheritance with the saints. But if we think we Jesus does not require repentance and obedience or that we can abide in disobedience and trust in some prayer we uttered years ago then its time to do some serious self-evaluation to see whether you are in the faith. For while the regenerate heart does not make one sinless but certainly the indwelling Spirit makes us mourn over sin so that we cannot abide there as a permanent place of residence.
"And his commands are not burdensome, for everyone born of God overcomes the world." 1 John 5:3, 4
"I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your impurities and from all your idols. 26 I will give you a new heart and put a new spirit in you; I will remove from you your heart of stone and give you a heart of flesh. 27 And I will put my Spirit in you and move you to follow my decrees and be careful to keep my laws." Ezek 36:25-27