The gospel is the power of God to salvation. Evangelism is the calling for every Christian to proclaim the message of the gospel. The power doesn't come from our ability or persuasiveness but by the Holy Spirit who works through our hearts of humility and reverence.
No one can come to Jesus unless the Father draws Him. I believe that is an important factor to remember. It is our responsibility to build a relationship with the lost around us and share enough love and grace with them that we can be available to share the gospel with them as the Holy Spirit leads. 
Evangelism is laborious! We tend to focus on the harvest in order to see someone saved and join our church without realizing there is an even greater need for those who need planting, cultivating, and watering. We forget those that do get saved have had someone or maybe several other faithful servants that have loved them and labored over their lives before we got there.
Evangelism is not about building our church.  God builds the church. When we focus on building instead of evangelizing we have stepped into an area that does not belong to us. 
Love your neighbor! Build that relationship! Watch to see what God is doing and be faithful when He calls you to get involved.