The relation between the Koran and human guidance

In the Koranic verses it is noticed that through religion human is guided:

1- Mankind was one nation, so God dispatched as heralds and warners. He sent the Book down along with them to bring the truth. So as to decide among mankind concerning whatever they had been disagreeing about. However only those to whom it was given disagreed about it out of envy towards one another after explanations had been brought them. By His permission God has guided those who believe to any Truth they may have disagreed about. God guides anyone he wishes to a straight Road. (2:213)

2- Yet they have no knowledge about it, they only follow guesswork. Conjecture will not help out in any way against the Truth. (53:28)

3- Are those who know, to be considered equal to those who do not know? Only prudent men reflect [on this]. (39:9)

4- Is someone who knows how whatever has been sent down to you from your Lord is the truth, like someone who is blind?  Only prudent persons bear it in mind. (13:19)