'Precaution' in the Bible

They set the table [for the doomed banquet], they spread out the cloth, they eat, they drink;“Rise up, captains [of Belshazzar’s court], oil your shields [for battle, for your enemy is at the gates]!”

My concern was because of the false brothers [those people masquerading as Christians] who had been secretly smuggled in [to the community of believers]. They had slipped in to spy on the freedom which we have in Christ Jesus, in order to bring us back into bondage [under the Law of Moses].

Finally, my fellow believers, continue to rejoice and delight in the Lord. To write the same things again is no trouble for me, and it is a safeguard for you.