"For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast." (Eph 2:8-9)
Who is the better Christian? The one who attends church on Sunday, reads his Bible daily, prays often and looks out for his elderly neighbor, or the one who attends church (both Sunday services, and Wednesday night), reads his Bible and participates in a study group, hosts a prayer meeting, volunteers at the homeless shelter 2 days a week, visits the nursing home and brings homebound church members meals?
Saved by grace means we didn't have to do anything to attain it (beyond acceptance). Our works come from the heart, not out of obligation. We do because it makes the Lord happy. We do because it is the right to do so. We do because there is a part of our heart that wants to make others happy, just as our Lord makes us happy. There are no "ulterior motives" in good works. There are no prizes for Christian of the Year. We lay these "crowns" at the feet of Jesus for it is he who tells us to do for others.
If you are worried about your works - do I do enough, are they worthy, are they true works - you aren't alone. In a world where material things matter more than the spiritual, it is a natural concern. It is not a contest to see who can help more homeless, who prays more or who hasn't missed a church service in 30 years - it's a way of life that allows you to live outside of yourself; it allows you to give of yourself to others.
Far too many people I've known had to run every event, chair every committee and decided every outreach leaving no opportunity for newer church members to do anything other than serve. They gain no more blessings than the member who can only collect the tickets at a pancake breakfast. If you are the person mentioned first (the one who has to do everything), step back and let someone else take the lead once in a while - it builds character for both and it's very humbling (which is, after all, what our Lord likes - humble Christians). If you're the person who only gets to collect the tickets, don't worry, the Lord knows your heart and sees your works and is glad!
Not by works, lest any man (or woman) should brag...