Ablaze! Initiative

I don't talk about religion much here but I should. For those that don't know I'm a Chrisitan who practices the Lutheran faith. My church is Ebenezer Lutheran Church located on the west side of Chicago. 1248 S. Harding to be exact. Anyway, my church is a part of the Missouri Synod - generally referred to as the LCMS (Lutheran Church - Missouri Synod). We are a small congregation and have been focusing on evangelism lately to grow. Our pastor has been focusing his sermons on being a contagious Christian. As part of being contagious Christians he has challenged us to participate in the Ablaze! initiative. Essentially the goal is the reach 100 million people over the next 10 years with the message that we are all sinners and it's is through God's love and the death of Jesus Christ that we are saved. It sounds pretty simple. But I notice that many Christians (myself included) don't talk to others (believers and non-believers) about God's gift to the world and how we don't have to do anything to get it but accept the fact that we are all sinners and through Jesus Christ we are saved. By opening our hearts to this promise we are saved. I wonder why?

{edit: I should say I wonder why Christians don't work harder to spread the "Good News". Especially when we know what it is and say we are proud to be who we are. I know why we are saved and that God loves us. I thought this might be confusing when I initially wrote it and I'm not wrong - it is.}