Why does the "way" people think change? Look at what has happened to our world over the past few decades, and how the insanity has snowballed in the past few years. The "way" people think and reason has been changed, and is being changed at a much faster pace now. The only way to have a sound mind and sound reasoning is to have a mind that is stayed on truth. Lies, fantasy, and misinformation corrupt the mind and the ability to think and reason properly is affected or done away with completely. The corruption in our minds comes mostly from influence of other people, with their corrupt minds and hearts and their insane opinions, especially about moral issues. This is why the Scripture tells us to "come out from among them and be ye separate, saith the Lord."