How does anyone believe. Belief come from God not the intellectual capacity of the believer.
Matthew 19:14
But Jesus said, Suffer little children, and forbid them not, to come unto me: for of such is the kingdom of heaven.
Acts 17:1-4;10-12,Rom.10:17,and 2 Tim.3:15-17 point out that man’s intellect has a part in producing faith. God does not force us against our will to believe and obey Him.