Salvation is not an intelligence test. Salvation is not an intelligence test but a preference test. The real issue is not whether we are convinced that God died on the cross for us, but whether we prefer to believe that God died on a cross for us. Jesus pointed out that what a person prefers will make all the difference when it comes to believing in salvation.
19 This is the verdict: Light has come into the world, but men loved darkness instead of light because their deeds were evil. 20 Everyone who does evil hates the light, and will not come into the light for fear that his deeds will be exposed. 21 But whoever lives by the truth comes into the light, so that it may be seen plainly that what he has done has been done through God. (John 3:19-21)
What does the cross say about people that stay in the shadows? The cross says that those in darkness love that state, and love what they do in that state. The cross also says that we have unsolvable moral problems, and irreconcilable differences with God that God and God alone can solve. If we come into the light, who is Christ, it means we prefer him to our sins. We can accept the truth of being sinners and of loving the wrong things. We prefer light to darkness.