He told me what he believed. He stated that belief like it was the end of the discussion and it was with his son. There was one significant problem. He would be hard pressed to validate what he believes from the pages of the Bible he takes to church.
Believing something does not make it true. Truth is not determined by what I believe, what my pastor believes, what the statement of faith of my church or denomination states, or what my society thinks is true. Truth is determined by what God says is true.
In John 14:1, Jesus said He was the truth... In 2 Timothy 3:14 - 17, Paul tells us that all Scripture is inspired by God. Multiple times in Psalm 119, David ascribes truth to God's Word. Bottom line, if what I believe cannot be validated by a proper study of God's Word, it is not true.
In the final analysis, that is what matters. As followers of Christ, our continual quest should be to plumb the depths of God's Word continually aligning what we believe with what the Word says.