The thoughts of those who are right with God can be trusted, but the words of the sinful are false. (Proverbs 12:5)
Have you ever thought to yourself, "Where did THAT thought come from?" There have been times when I found myself considering some thought that seemed to come 'out of left field' without any idea of its source. I had to stop myself, actually reflect on the 'wisdom' of the thought, and then reject it without further thought because there wasn't much 'wisdom' in it at all. I think this is why scripture does so much to warn us of the power of the mind - thoughts can be good or evil, but they can also be somewhere in-between. We have both the requirement and authority to examine our thoughts and consider the 'source'. If the 'source' isn't bearing up to the truth we know about God, how he works, what he says about us, or what he says about others, it is likely not the best thought to be dwelling upon.
Let me assure you I know how hard it is to 'change' a thought pattern once it gets established in our own lives, so why are we constantly trying to meddle in someone else's lives over their thought lives. There is more truth to the saying, "Curiosity killed the cat", than we may actually appreciate. Meddling in the affairs of another will get us into trouble, for sure. That said, God actually helps us 'sort out' our 'unreliable thought patterns' when we are with close friends who are also following close to Jesus. Notice I said they were following close to Jesus - it is unwise to run our thoughts past someone who is not aware of what scripture outlines as the boundaries for our lives. Wise counsel doesn't tell us which thought patterns are right or wrong, but it will help us to determine where there may be any untruth in what we are considering.
The man right with God can trust his thoughts. Why? God's 'governance' over our minds makes it easier to 'spot' any untruth when it presents itself to us. Have you ever had one of those moments when you just knew something 'felt a bit off' about a circumstance, opportunity, or idea? That was God's Spirit within you helping you to 'sort out' those thoughts about the matter at hand. Some think 'governance' is kind of a harsh word to describe the life God wants with us, but all obedience is really submission to some form of 'governance' in our lives. We can submit to our own governance if we desire, but that probably won't get us very good things. We can submit to the governance of someone we look up to but putting our trust in the authority of any man or woman is not a good thing because they are equally as fallible as we are! Trust in the Lord and realize the 'freedom' of governance that actually provides the highest degree of protection over your life - including your thought life. Just sayin!