We should want to evangelize because of the joy that God puts in our hearts. Ultimately, that's the best reason for sharing our faith.
Mark DeverIt's fine to deal with people's doubts and explain why they have good reasons to believe in Christ. But until we tell them the good news of Jesus Christ, we haven't done our job. They need a saviour that God has provided them in Christ. Once they know that, we can do as much apologetics as we need to.
Mark DeverOnce we see more of our need and understand more of what Christ has done for us, he will become more precious to us. And this, in turn, will enable our obedience far more than sheer grunt effort.
Mark DeverWe can't know at any given time how God will bless our faithful witness. So the apparent numerical growth of the church is never a good guide to how faithful we have been in evangelism.
Mark Dever