He does not want to believe. He simply cannot understand and respond to the gospel on his own. Clearly, the Father does not draw everyone to himself. The answer is that the Father chooses those to whom he gives saving faith. Since no one wants or deserves this saving faith it must be purchased on the cross by Jesus.
Faith is a gift.
The question that bothers some has to do with the fact that faith on the other hand is of the feminine gender. Normally, the noun and the pronoun agree in gender. The gender for grace is also feminine, the same as faith. Since we have already seen that it is impossible for man to believe on his own it is absolutely necessary that faith be purchased on the cross along with all the rest of our salvation. So to say that Jesus paid for the sins of all, but only those who believe actually get their sins paid for, is in effect saying that no one is going to believe, since no one is able to believe on his own.