'Fixed' in the Bible

But if I am doing the very thing I do not want to do, I am no longer the one doing it [that is, it is not me that acts], but the sin [nature] which lives in me.

See then that God is good but his rules are fixed: to those who were put away he was hard, but to you he has been good, on the condition that you keep in his mercy; if not, you will be cut off as they were.

Let love be without deceit. Be haters of what is evil; keep your minds fixed on what is good.