'Unstable' in the Bible

So then, was I indecisive or capricious when I was [originally] planning this? Or the things I plan, do I plan in a self-serving way like a worldly man, ready to say, “Yes, yes” and “No, no” [at the same time]?

Impress on those who are rich in the present age that they must not be haughty nor set their hopes on riches--that unstable foundation--but on God who provides us richly with all things for our enjoyment.

A double minded man is unstable in all his ways.

Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children:

As also in all his epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as they do also the other scriptures, unto their own destruction.