What do I cleave to?

Words sometimes turn out to mean the opposite from what they used to. Cleave is one of these words. It has been confusing to me unless I recognize this contradiction. And also realize that cleave is not alone among words. They are called contronyms.

Cleave can mean "To stick; to adhere;", as in "If I do not remember thee, let my tongue cleave to the roof of my mouth;" (Ps 137:6)

Similarly it means "To unite or be united closely in interest or affection; to adhere with strong attachment." as in "Thou shalt love thy wife with all thy heart, and shalt cleave unto her and none else." (D&C 42:22) and "forsake all evil and cleave unto all good, that ye shall live by every word which proceedeth forth out of the mouth of God." (D&C 98:11)

The opposite meaning is seen in cleaver, a knife that is used to cut meat.

So what do I adhere to? To what have I affection and am strongly attached to? What competes for my attention? That might distract me from the most important?