For something to "fail" in the Bible means there is not enough understanding of truth and desire for good for someone to attain a higher spiritual state -- and possibly not enough to overcome false thoughts and the desire for evil at all. "Abate" has similar meaning but in an opposite sense, usually referring to the lessening of evil and falsity at the end of a state of temptation.

In Genesis 8:3, Deuteronomy 34:7, Judges 8:3, and Leviticus 27:18, the abating of the flood waters signifies the cessation of temptations. (Arcana Coelestia 843, 849)

(Референце: Arcana Coelestia 857, 5969, 6122, 8395)

6122. 'If the silver is lacking' means if truth could no longer be seen by them. This is clear from the meaning of 'the silver lacking' as a lack of truth, thus that truth is no longer to be seen, dealt with above in 6116, 6119. Truth is said not to be seen because in a state of desolation truth seems to have fled. But it is in fact present, for all truth and good that the Lord ever grants man, spirit, or angel remains. None is ever taken away from them, but in a state of desolation they become so obscured by the person's selfhood that they cannot be seen. Once a state of light returns however, they are made present and to be seen. This shows what is meant by truth's inability to be seen.