The Bible plainly teaches that only those who personally, consciously, and explicitly confess Jesus Christ as Lord possess eternal life. All others will face the holy and just wrath of God in hell throughout eternity.
Throughout the NT, the biblical writers uniformly describe a coming fixed and final divine judgment. Revelation 20:11-15 describes this scene in which all persons, both living and dead, will stand before God to be "judged according to their works." John wrote, "Anyone not found written in the book of life was thrown into the lake of fire." The "book of life" lists all those who have believed and obeyed Jesus Christ.
Jesus Himself said, "I will give to the thirsty from the spring of living water as a gift ... But the ... unbelievers ... their share will be in the lake that burns with fire and sulfur, which is the second death" (Rv 21:6-8). This passage reveals central truths concerning who will be saved. Redemption comes by grace through faith in Christ, apart from individual merit. Those who have not believed are deemed "unbelievers" and will receive a just and endless punishment in hell.
During His earthly ministry, Jesus talked more often about final judgment than He did about heaven (see, for example, Mt 25:41; Lk 16:23-31). He also warned anyone who rejected Him, "Just as the weeds are gathered and burned in the fire, so it will be at the end of the age" (Mt 13:40). Throughout the NT, the apostles consistently echoed their Lord's theme (see 2 Th 1:5-9; Heb 9:27; 2 Pt 3:7).
Despite repeated scriptural emphasis to the contrary, universalists commonly raise three objections to the exclusivity of the gospel.
All religions are equally true; therefore everyone will be saved. This claim is easily disproved. For example, a Hindu might say all religions lead to God, while a Christian asserts that Jesus is the only way to the Father. In order to stay true to his conviction, the Hindu must say that the Christian's exclusive claim is wrong. But once he has said this, he has violated his dictum that all religions are equally valid. The two beliefs cannot both be right. Therefore it cannot be concluded on this basis that all persons will be saved.
God will give all human beings an opportunity to accept the gospel after death. Despite a lack of biblical evidence in its favor, this view teaches that God will offer a final chance for people to repent after death and before the judgment. On the contrary, the Scriptures clearly indicate that once a man dies, it is too late for him to repent and turn to God (see Mt 25:35-46; Lk 16:19-31). "It is appointed for people to die once-and after this, judgment" (Heb 9:27
What about the "man on the island" who has never heard the gospel? It would not be fair for God to send such a person to hell for not believing in Jesus. This argument from emotion is often heard and particularly dangerous. If it is true that God is obligated to save everyone who has not heard the gospel, then we might be better advised to recall all missionaries and stop proclaiming the gospel. Of course, the Bible does not countenance such a God-dishonoring approach. The "man on the island," like all people, is in desperate need of the good news about the forgiveness of sins through Jesus Christ.
Extracted from the Apologetics Study Bible.