The Great Commission
The last command of the risen Christ, given to ordinary people
When the risen Jesus left His followers, He did not tell them to circle the wagons, protect what they had, and wait quietly for heaven. He told them to go. The very last instructions He gave, standing on a hillside before ascending, were a commission to carry the good news to the whole world, and to keep going until it had reached the ends of the earth. The church has called this the Great Commission, and it is, in a real sense, the church's job description, the reason a community of forgiven people is left in the world at all rather than taken straight home. And the striking thing is who it was given to: not religious experts, but a handful of ordinary, frightened, recently-failed disciples.
The marching orders
The commission itself is brief and total. With all authority backing it, Jesus said: "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world" (Matthew 28:19-20). Notice the verbs: not merely "convert" but "make disciples," and then "baptizing" and "teaching them to observe." The goal is not decisions but disciples, people learning to follow Jesus for life (see baptism and a faith that obeys). And just before He ascended He set the trajectory: "ye shall be witnesses unto me both in Jerusalem, and in all Judaea, and in Samaria, and unto the uttermost part of the earth" (Acts 1:8), home first, then outward, then everywhere.
Given to everyone, not the professionals
It is a modern mistake to think evangelism is the job of clergy and missionaries while ordinary Christians watch. The Bible knows nothing of that division. When persecution scattered the early church, it was not the apostles but the rank-and-file believers who carried the message: "they that were scattered abroad went every where preaching the word" (Acts 8:4). A witness is simply someone who tells what they have seen and heard, and that is a thing any believer can do. The man Jesus healed of blindness was no theologian and said so; when the experts tried to trap him he answered with disarming honesty, "one thing I know, that, whereas I was blind, now I see" (John 9:25). You do not need to win every argument or answer every question. You need to tell the truth about what God has done in you.
The motive: love, not arrogance
Mission has sometimes worn an ugly face, conquest, coercion, cultural pride, and it is right to grieve that and renounce it. But the true motive underneath the commission is love, and a sober reality: that people apart from Christ are genuinely lost, and the news that could reach them only reaches them if someone brings it. Paul reasons it out plainly: "how shall they believe in him of whom they have not heard? and how shall they hear without a preacher?" (Romans 10:14). To keep silent about a cure you have found is not humility; it is a strange unkindness. We tell others not because we are better than they are, we are beggars who found bread, but because the bread is real and they are hungry too.
The manner: gentleness and respect
How the message is carried matters almost as much as that it is carried. The Bible's instruction is the opposite of the loud, hectoring caricature: be ready, but be gentle. "Be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear" (1 Peter 3:15). Note that it assumes people will ask, which means a life worth asking about comes first. Our words are to be "alway with grace, seasoned with salt" (Colossians 4:6). Witness is not winning arguments or closing sales; it is one beggar telling another where the food is, with the same gentleness we were once shown.
A great deal of pressure lifts off evangelism once you see the division of labor. Our job is to be faithful witnesses; it is God who opens hearts and gives the increase. "I have planted, Apollos watered; but God gave the increase" (1 Corinthians 3:6). No one was ever argued into the kingdom by force; the Spirit must give the new birth (see born again). This frees us from two errors at once: the manipulation that tries to manufacture conversions, and the despair that takes every "no" as our personal failure. You are responsible to love and to tell, not to produce a result only God can give. Sow generously, leave the harvest to Him, and let no fear of rejection silence you.
Where this lands
The commission ends with a promise that makes the whole thing bearable: "lo, I am with you alway." We are not sent out alone or on our own strength; the One who commands the going goes with us. And the destination is breathtaking, a future John was shown of "a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues" (Revelation 7:9), the long obedience of ordinary witnesses finally gathered home. It was always God's purpose to reach the nations; He said so to His Servant centuries before: "I will also give thee for a light to the Gentiles, that thou mayest be my salvation unto the end of the earth" (Isaiah 49:6). You are one small, real part of that. Tell someone what you have seen (see faith that acts).
Related: Faith Is a Verb, Spiritual Gifts, Baptism, Born Again, Hope, and The Witnesses. Scripture from the King James Version, linked to BibleHub; the words of God are marked in gold, the words of Christ in purple.