Every believer should evangelize. I know some Christians think that evangelism is only for people with special gifts for it, but I don't believe the New Testament teaches that. While Paul does say that some believers have the call to be evangelists, all of us have the responsibility of evangelism.
I heard about a pastor in a church of 5,000 people who employed two seminary students whose main responsibility was to get four new people baptized each week. When asked, "What happens if they can't meet the quota?", his response was, "Then I'll find two students who can". This man wasn't even remotely interested in true gospel preaching. He was results-driven.
I think it's unhelpful to suggest that the task of evangelism is essentially the responsibility of ministers.
As a pastor, I have the opportunity every week to share the gospel publicly in a way that most of the members sitting in our church do not. However, that doesn't absolve them of the responsibility for reaching others with the gospel.
