I have long thought about our good works done as Christians as being similar to the good work of a six year old helping her mother in the kitchen. The work that the six year old does is accepted with praise and gratitude by her mother not because of the quality of the work or because it actually helped the mother all that much but because the mother loves her daughter and wants to encourage even her beginning attempts to do good.
God calls our works done in faith and in regard to His will good not because they are that good in themselves or needed by God but out of His love for us and to encourage us to grow in faithful living.