GC I have been studying the Bible for while now. Why is it that there are so many that don't understand.?

Why are there so many lost souls? I've noticed that most people that either don't believe in God or Jesus Christ are young people. They speak without understanding, many repeat what they hear without knowledge. They presume to be wise unto themselves but only make fools of themselves when they speak. Why do they ask questions about God, when the answers are in the Bible? Why don't they study the bible? I'll tell you why, they deny the truth, they assume to be wiser than God. But I will tell you this, in the hour of Judgement they will lament their own foolish folly. May God have mercy on their souls.