While there is the spiritual gift of evangelism (Eph. 4:11), the rest of us should do the work of an evangelist (2 Tim. 4:5), being ready to give a reason for the hope within us (1 Pet. 3:15). If we see someone stumbling toward destruction, we should try to hold the person back (Prov. 24:11).
Increasingly evangelism is seen as a process moving from ignorance and indifference toward God, toward the fervent and joyful worship of the triune God. I cannot conceive of a more wonderful miracle among humankind.
As many have correctly noted, we’re not commanded to go into all the world to witness, but to make disciples of all people groups (Matt. 28:19-20). One way to measure our earthly impact is the number and quality of the disciples we’ve made.
Both evangelism and discipling are skills learned. I’ve been helped by reading books by D. James Kennedy (Evangelism Explosion), Neil Cole (Search and Rescue), Jerry Trousdale (Miraculous Movements), and Joseph Aldrich (Life-Style Evangelism) on these subjects, and by the discipling ministry of my current pastor, Joe Novenson. Cole taught me the invaluable lesson that the form of discipleship changes with the length of the relationship, and becomes opportunistic, coming alongside as the need arises (much like parenting adult children). Novenson taught the value of giving books that speak to needs of those we’re discipling, simply by giving me books. Much more wisdom than ours is transmitted, and Amazon.com provides one very easy channel.
Evangelism leads to the study of apologetics, to deal with more difficult questions and objections. Many of CS Lewis’ books are supremely eloquent apologies for Christianity, such as Mere Christianity. I’ve been helped by Gleason Archer’s Bible Difficulties, and books by Josh McDowell (Evidence that Demands a Verdict among them), and a book by Ravi Zacharias (Deliver Us from Evil, which explains current Western culture well), and Kenneth Boa (I’m Glad You Asked). Helpful has also been Michael J. Behe’s Darwin’s Black Box, which powerfully but scientifically discredits evolution dogma by making the case for Intelligent Design. Despite the post-modern trend away from propositional truth, we are to give a reason for the hope within us, rather than a feeling or personal opinion.
The Internet provides many excellent apologetics websites (excellent sites dealing with cults and world religions aren’t specifically mentioned here):