It is a tragic and ugly thing when Christians lack desire, and are actually reluctant, to share the precious knowledge that they have with others whose need of it is just as great as their own. It was natural for Andrew, when he found the Messiah, to go off and tell his brother Simon, and for Philip to hurry to break the good news to his friend Nathanael (Jn 1:40ff.). They did not need to be told to do this; they did it naturally and spontaneously, just as one would naturally and spontaneously share with one’s family and friends any other piece of news that vitally affected them.
There is something very wrong with us if we do not ourselves find it natural to act in this way: let us be quite clear about that. It is a great privilege to evangelize; it is a wonderful thing to be able to tell others of the love of Christ, knowing that there is nothing that they need more urgently to know, and no knowledge in the world that can do them so much good. We should not, therefore, be reluctant and backward to evangelize on the personal and individual level. We should be glad and happy to do it. We should not look for excuses for wriggling out of our obligation when occasion offers to talk to others about the Lord Jesus Christ. If we find ourselves shrinking from this responsibility and trying to evade it, we need to face ourselves with the fact that in this we are yielding to sin and Satan.
If (as is usual) it is the fear of being thought odd and ridiculous, or of losing popularity in certain circles, that holds us back, we need to ask ourselves in the presence of God: Ought these things to stop us loving our neighbor? If it is a false shame, which is not shame at all but pride in disguise, that keeps our tongue from Christian witness when we are with other people. We need to press on our conscience this question: Which matters more-our reputation or their salvation? We cannot be complacent about this gangrene of conceit and cowardice when we weigh up our lives in the presence of God. What we need to do is to ask for grace to be truly ashamed of ourselves, and to pray that we may so overflow in love for God that we will overflow in love for our fellow men, and so find it an easy and natural and joyful thing to share with them the good news of Christ.
—adapted from Evangelism and the Sovereignty of God by J.I. Packer