The only way one can ever know the truth is to have Jesus/Holy Spirit teach him or her.Then why do we have a Bible, and why has God allowed to exist for 2000 years?
First of all the bible has not existed for two thousand years. Again it does not take intelligence to read the bible. It only takes the ability to read, but to understand the written Word of God it takes the Holy Spirit.
Now you say you’re an intelligent person so read the following verse and see if you can understand what it says.
(1 Corinthians 2:10-16) “These are the very things that God has revealed to us through the Spirit, for the Spirit reaches the depts. Of everything, even the depths of God. After all, the depths of a man can only be known by his own spirit, not by any other man, and in the same way the depths of God can only be known by the Spirit of God. Now instead of the spirit of the world, we have received the Spirit that comes from God, to teach us to understand the gifts that he has given us. Therefore we teach, not in the way in which philosophy is taught, but in the way that the Spirit teaches us: we teach spiritual things spiritually. A spiritual man, on the other hand, is able to judge the value of everything and his own value in not to be judged by other men. As scripture says;’ who can know the mind of the Lord, so who can teach him?’ But we are those who have the mind of Christ.