'Fail' in the Bible

Sell that which you have, and give gifts to the needy. Make for yourselves purses which don't grow old, a treasure in the heavens that doesn't fail, where no thief approaches, neither moth destroys.

I tell you, make for yourselves friends by means of unrighteous mammon, so that when you fail, they may receive you into the eternal tents.

but I prayed for you, that your faith wouldn't fail. You, when once you have turned again, establish your brothers."