I think he is right! People do believe what they want to.
That's why there are so many different religions in the world today. What do you think? Will mankind ever unitedly serve God to His glory? If mankind adopts our Heavenly Father's way of thinking, would worldwide unity be possible? How though can we know our Creator's intimate thoughts? One way is by observing the creation around us, even our own bodies, contemplating on how wonderfully made we are! Everything that man has invented has already existed some where in nature. We can learn about God's qualities by observing the book of creation. (Romans 1:20)
What about the laws that govern man? Does God give us guidelines on how to live the life he gave us? Yes, while we are endowed with free will, we are not left to ourselves to figure things out. As a loving Father who cares for his children God gave us written information. We learn about God's thoughts and feelings, yes, His viewpoint and what he requires of us. We can then, as loving children imitate the One who made the heavens and the earth! (Isaiah 48:17; Ps 25:8, 9)
He used some 40 human secretaries over a period of 16 centuries to record it, but God himself actively directed the writing by his holy spirit. The Bible truly is inspired by God. (2 Tim 3:16, 17)
How then can we know we have the correct interpretation? Two things can help us to understand the Bible correctly. First, consider the context (surrounding verses) of any statement. Next, compare texts with other statements in the Bible that deal with the same subject. When we do that we are allowing God's word to guide our thinking, and the interpretation is not ours but His. This is what I endeavor to do when posting Bible thoughts. (Also, we ask in prayer to understand God's thoughts)