Heidelberg Catechism, Week 24

Lord’s Day 24

62. But why cannot our good works be the whole or part of our righteousness before God?

Because the righteousness which can stand before the judgment seat of God, must be perfect throughout and entirely conformable to the divine law,¹ but even our best works in this life are all imperfect and defiled with sin.²

¹ Deut 27:26; Gal 3:10; ² Isa 64:6; Php 3:12; Jas 2:10

63. Do our good works merit nothing, even though it is God’s will to reward them in this life and in that which is to come?

The reward comes not of merit, but of grace.¹

¹ Mt 5:12; Lk 17:10; Rom 11:6; 2 Tim 4:7-8; Heb 11:6

64. But does not this doctrine make men careless and profane?

No, for it is impossible that those who are implanted into Christ by true faith, should not bring forth fruits of thankfulness.¹

¹ Mt 7:18; Lk 6:43-45; Jn 15:5; Rom 6:1-2

 (URC Learning)

I think this is my favorite section of the Catechism, mainly because it makes quick work of the 'cheap grace' argument that some folks quickly throw out when confronted by God's grace.  While our good works do nothing to gain favor with God, salvation by grace does not allow a professing Christian to live in a way to disregard the moral law or the teachings of scripture.  Grace doesn't lead to lawlessness, but to gratitude.