I find my biggest temptation as a long-term Christian is to work for my faith instead of receiving grace, to take credit for the Lord's work and to take the blame when I fail. I know I could be living out my faith in a better, bolder way that would hopefully send people flocking to God because of the good news my life preaches. When I'm not doing big, bold things for the Lord, I feel like I'm failing, that I need to try harder. I think of the early church, who lived to share and care for everyone. And they grew in numbers every day. 
Yesterday, I read about the early church again in Acts 2 and noticed the last sentence for what seems like the first time. It says, "And each day the Lord added to their group those who were being saved." What this means is that even though this was the perfect representation of what it means to live a Christian life, the people weren't persuaded by what they saw but by the Lord. It is truly the Lord who saves, not our actions no matter how great they are. The flip side of this, as I was reminded at this weekend's service, is that we can't really do anything to cause someone to become a Christian (that is the Lord's doing) but we can cause people to sin, which is a horrible thing to do (see Mark 9:42).