A great word from Pastor John Piper about the on going need to bring our thinking into conformity with Christ.
Until your mind is conformed to the mind of Christ, the teaching of this text will probably produce conflict, not comfort. This text is meant to comfort you and strengthen you and give you confidence that the best and worst things in your life will work for your good, because you love Christ and are chosen and predestined for glory. But it will only have this effect when God grants you a measure of the mind and spirit of Christ.
I don't say this to scold you or condemn you if you struggle. Just the opposite. I say it to encourage you that just like behavioral conformity to Jesus is a life-long battle with wrong deeds, and emotional conformity to Jesus is a life-long battle with wrong feelings, so intellectual conformity to Jesus is a life-long battle with wrong thinking. So I am never surprised when some folks stumble over the harder teachings of Scripture. Conformity to Christ does not come all at once, neither, behavioral, nor emotional, nor intellectual.