Question: "Why is 'accepting Christ' mentioned in evangelism when it is not in the Bible?"
Answer: Ever since the New Testament era, Christians have found the need to coin new terms to simplify or explain various doctrines. We reference the Trinity and the protoevangelium, although neither term occurs in the Bible. While “accepting Christ” is not a phrase found in the Bible, it does have a biblical basis, just as Trinity does.
Jesus and His followers often called salvation and the subsequent indwelling of the Holy Spirit a “gift.” For instance, Jesus told the woman at the well, “If you knew the gift of God and who it is that asks you for a drink, you would have asked him and he would have given you living water” (John 4:10). Paul said, “The wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord” (Romans 6:23).
By definition, a gift is not forced—but it must be accepted. A gift can be refused. John the Baptist said of Jesus, “He testifies to what he has seen and heard, but no one accepts his testimony. The man who has accepted it has certified that God is truthful” (John 3:32-33). The word accept here is a translation of the same Greek word translated “take” in Revelation 22:17: “Whoever wishes, let him take the free gift of the water of life.” “Take,” “accept,” “receive”—this is what we are to do with the free gift of God. Salvation is offered, but we must accept the offer in order to receive the gift. Since we do this by exercising faith in Christ, the phrase “accept Christ” is simply shorthand for saying “place faith in Christ and receive His salvation.”
The goal of using terms like “accept Christ” is to communicate the truth more effectively to someone with limited biblical understanding. As long as a term is theologically correct and aids understanding, it need not be part of the biblical vocabulary. If, during evangelism, a certain term causes misunderstanding, then it’s good to jettison the confusing term and patiently explain the truth from Scripture. While the phrase “accept Christ” does not appear in the Bible, the concept of receiving a gift does, and the phrase seems to works well in most evangelistic contexts.