"All authority in heaven and on earth has been given to me. Therefore go and make disciples of all nations, baptizing them in the name of the Father and Son and of the Holy Spirit, and teaching them to obey everything I have commanded you." - Matthew 28:18-20
The meaning of the original word translated "go" in the English language means "as you are going". We are to reach out and share the Good News of forgiveness of sin and salvation through Jesus Christ with others ... as we are going in our daily lives. As you are going ... at work ... at school ... at the mall ... at the restaurant ... at the bank ... when you are with family ... when you are with friends... The word meaning "as you are going" implies a lifestyle of being obedient and faithful to Jesus and His command to reach out to others and make disciples. It does not mean to "do" evangelism occasionally, or to have an occasional evangelism event, but it means to have an obedient lifestyle of continually reaching out to others.
It also signifies a deliberate effort to reach outside the walls of your church to share the Gospel - in your community, in your nation, and in all other nations. In many churches the majority of the members leave the preaching of the Gospel to the pastor, and at best they occasionally invite someone to visit their church. This is not what Jesus meant when he said "go". If you study Jesus' life, you see that He was constantly going to where the lost people were. He did not wait around for the people to come to Him, He went to where they were to share the message of God's love and salvation. We cannot fulfill the Great Commission in Matthew 28 by sitting around in our churches and by staying in our comfort zones.