'Ought' in the Bible

yet he has no [substantial] root in himself, but is only temporary, and when pressure or persecution comes because of the word, immediately he stumbles and falls away [abandoning the One who is the source of salvation].

“Woe to you, [self-righteous] scribes and Pharisees, hypocrites! For you give a tenth (tithe) of your mint and dill and cumin [focusing on minor matters], and have neglected the weightier [more important moral and spiritual] provisions of the Law: justice and mercy and faithfulness; but these are the [primary] things you ought to have done without neglecting the others.

At that time many will be offended and repelled [by their association with Me] and will fall away [from the One whom they should trust] and will betray one another [handing over believers to their persecutors] and will hate one another.