2 Corinthians 4: 3-4
3And even if our gospel is veiled, it is veiled to those who are perishing, 4in whose case the god of this world has blinded the minds of the unbelieving so that they might not see the light of the gospel of the glory of Christ, who is the image of God.
The unbelievers do not believe in Jesus Christ because they do not see their need for Jesus Christ; they do not see their need for Jesus Christ because they do not see their sinfulness, wrechted and depraved nature before God; they do not see their sin and need for being saved, because they do not know what sin is and the consequence thereof; they do not know what sin is, because they do not see God's Holy Nature and Justice and wrath to punish them for breaking God's Law; hence, being blinded to God's wrath, they do not see God's great Love for which He Loved us, in that while we were yet sinners, Christ Died for the ungodly, Romans 5:6. The unbeleivers do not believe in Jesus Christ because they do not believe they need to be saved from the wrath of God; the unbelievers do not love God, because they hate God; the unbelievers hate God because they are dead to God and have a great need to be Born-Again by the Holy Spirit, and be made alive by the Holy Spirit, in order to see their great need for Salvation from the great miry depths of their sinful condition and their need for Jesus to Save them from the wrath of God abiding upon them now and finally in the Lake of Fire for all eternity! They will believe then, but it will be too late when the eternal wrath of God is unveiled in the Lake of fire and great torment; they will believe then, when the afflictions of their eternal torment is constsntly abiding on them and the smoke of their torment is forever rising, for the consequence of their sinful nature ruling their lives this side of eternity!
Don't you know? The unbeliever needs to be Saved from the Wrath of God constantly abiding!