Commissioning his disciples to "Go into all the world and preach the gospel to all creation" (Mark 16:15), their task was far more than imparting correct religious information, though it involved that: The gospel contains God's expressed desire to have a relationship, to have fellowship with people. Fellowship is having things in common. Paul speaks of "God who has called you into fellowship with his Son Jesus Christ our Lord" and John affirms "our fellowship is with the Father and with his Son, Jesus Christ." (1 Corinthians 1:9; 1 John 1:4).
God's longing to have fellowship, to have an intimate relationship with people is a common theme throughout Scripture. For example, Moses reminds Israel how "the Lord your God carried you as a father carries his son." (Deuteronomy 1:31). Through the prophet Isaiah God says to Israel, "Even to your old age and gray hairs I am he, I am he who will sustain you. I have made you and I will carry you." (Isaiah 46:4). While lamenting the sinfulness of Jerusalem Jesus speaks of God's holy desire to have a meaningful relationship with them: "O Jerusalem, Jerusalem," he says, " you who kill the prophets and stone those sent to you, how often have I longed to gather your children together, as a hen gathers her chicks under her wings, but you were not willing." (Matthew 23:39). These images convey what it is that God is after - a relationship with people.
Jesus says that eternal life is to "know you, the only true God, and Jesus Christ whom you have sent." (John 17:3). Knowing God, and knowing about God are two entirely different matters. Let me explain: There was never a time in my life when I did not believe in God or that Jesus is the Son of God. I always believed that Jesus died and rose again. I would never have denied this, but what I did not have was a relationship with him as my Father. I had correct information yet didn't know him as my Father and my Saviour. Paul caught the correct meaning when he said, "I know in whom I have believed." (2 Timothy 1:12). It's not what you know, it's who you know.
Evangelism is not about getting people to obey a set of rules, (though there are commands to be obeyed), to belong to the right group, (though one must belong to the body of Christ), to hold the correct position on a selected number of issues, to have loyalty to a particular brand of Christianity; yet much of present day evangelism falls into this category, therefore we should not be surprised at the sectarian and divisive spirit that is evident on occasions. Evangelism is telling people they are passionately loved by God who longs to embrace them as his sons and daughters, and that through the death and resurrection of his Son he had made provision for that to happen.
This is evangelism and will result in people being converted to the Lord Jesus Christ.