As Christians we have a responsibility to evangelize. The Coptic Church's history is one of evangelizing the whole world.
Examples are abound.
Our saints spread the Gospel to Switzerland and Irland. There are several references in the Bible about the responsibility of each one of us with regard to evangelism. Here are some of these references. The above verses point to the importance of communicating what we know of Christ's work to others. This is even clearer in the words of our Lord before His ascension.