In a blog post, Gracious Merit in the Bible, I interacted with, and refuted a Reformed Protestant apologist who took umbrage with the Latter-day Saint view of (gracious) merit. Other important texts proving the concept of gracious merit in the Bible include the following (the following are from the NRSV):
They are to do good, to be rich in good works, generous and ready to share, thus storing up or themselves treasure of a good foundation for the future, so that they may take hold of the life that really is life. (1 Tim 6:18-19)
From now on there is reserved for me the crown of righteousness, which the Lord, the righteous judge, will give me on that day, and not only to me but also all who have longed for his appearing. (2 Tim 4:8)
For God is not unjust, he will not overlook your work and the love that you showed for his sake in serving the saints, as you still do. (Heb 6:10)