Heidelberg Catechism, Lord’s Day 24
Q62. Why can’t our good works
be our righteousness before God,
or at least a part of our righteousness?
A62. Because the righteousness
which can pass God’s judgment
must be entirely perfect
and must in every way measure up to the divine law.
But even our best works in this life
and stained with sin.
Q63. How can our good works
be said to merit nothing
when God promises to reward them
in this life and the next?
A63. This reward is not earned;
it is a gift of grace.
Q64. But doesn’t this teaching
make people indifferent and wicked?
It is impossible
for those grafted into Christ through true faith
not to produce fruits of gratitude.