6 reasons to witness the Gospel -
First, because Jesus commands you to: "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit," (Matt. 28:19). Also, Ezek. 3:11 says, "and go to the exiles, to the sons of your people, and speak to them and tell them, whether they listen or not..."
Second, you must witness because you love the unsaved (if you don't, you should). The most loving thing you can do is present the gospel in hopes of bringing others to salvation. Galatians 5:22 lists love as one of the fruit of the Spirit. It is love's nature to give. Take for example John 3:16, "For God so loved the world that He gave His only begotten Son..." Love gives, and if you have only a small portion of His love, you will want to give to others.
Third, witness because it is a wise thing to do. Prov. 11:30 says, "...he who is wise wins souls." Now, I know I am not a very wise person. But, since God says I'll be wise to win souls, or try to, then great, let me at it. I want to be wise in God's sight.
Fourth, witness to keep people out of hell. Hell is a terrifying place of utter anguish and eternal separation from God. Those who are not saved go there. Witnessing is an attempt to keep them out of hell.
Fifth, witness because it pleases God and brings glory to His name.
Sixth, witness so they may find the love and fellowship of God (1 John 1:3), the greatest of all treasures. I can think of no greater gift than salvation. It frees the sinner from sin, it delivers the lost from damnation, and it reveals the true and living God to those who don't know Him.
The angels of heaven rejoice greatly when anyone passes from judgment into salvation (Luke 15:10). Shouldn't we as Christians rejoice too? Shouldn't we weep over the lost? Shouldn't we ask the Lord of the field to send laborers into His harvest (Luke 10:2)? Certainly! The salvation of others is the goal of your efforts. The love of God is your motive. Is there anything greater? So, give.
Read this excerpt of an email to Ray Comfort from an atheist.
You are really convinced that you've got all the answers. You've really got yourself tricked into believing that you're 100% right. Well, let me tell you just one thing. Do you consider yourself to be compassionate of other humans? If you're right, as you say you are, and believe that, then how can you sleep at night? When you speak with me you are speaking with someone who you believe is walking directly into eternal damnation into an endless onslaught of horrendous pain which your 'loving' god created, yet you stand by and do nothing.
If you believe one bit that thousands every day were falling into an eternal and unreachable fate, you should be running the streets mad with rage at their blindness. That's equivalent to standing on a street corner and watching every person that passes you walk blindly directly into the path of a bus and die, yet you stand idly by and do nothing. You're just twiddling your thumbs, happy in the knowledge that one day that 'walk' signal will shine your way across the road.
Think about it. Imagine the horrors Hell must have in store if the bible is true. You're just going to allow that to happen and not care about saving anyone but yourself? If you're right then you're an uncaring, unemotional and purely selfish (expletive) that has no right to talk about subjects such as love and caring.
Everyday there are approximately 150,000 worldwide who pass from this life into another. If you are a Christian, you have been given a mandate from the Lord Himself to go into all the world and preach the Gospel to every creature.
In the letter above, James makes a valid point; "If you believe one bit that thousands every day were falling into an eternal and unreachable fate, you should be running the streets mad with rage at their blindness. That's equivalent to standing on a street corner and watching every person that passes you walk blindly directly into the path of a bus and die, yet you stand idly by and do nothing. "
James is right - If we believe one bit that people are dying and going to hell we should make it a priority to witness to as many people as we can while we still have a breath.