It provides a natural humility as we look to the Lord and not to ourselves. This does not mean that we can willfully sin or take for granted God's grace expecting him to overlook it. God knows the intents of our hearts, and he will judge us by them.
The old testament increases my fear of God. That's one of the main reasons I like reading the old testament. God is the same today, yesterday, and forever. His wrath is being halted only through Jesus Christ the spotless lamb and sacrifice for our sins. Anything outside of Christ will guarantee God's wrath.
This is why we cannot be prideful and look to our own works, or to holding up an image of perfectionism based on works. There is only one who is perfect and spotless and that is Jesus Christ the one who is worthy to open the book of life and judge the world. Let's not discount his work for us by trusting our own works outside of him.