Jesus says strong warnings about the hypocrites and false teachers as does Peter. They will be among you, but they are not of you. They show by their fruit who they are. Just like Paul wrote about, they are examples for us to not do the things they do. These things are to be viewed as learning experiences for the true church to not be like them.
1 Corinthian 10
1For I do not want you to be ignorant, brethren, that our forefathers were all under and protected by the cloud [in which God’s Presence went before them], and every one of them passed safely through the [Red] Sea,
2 And each one of them [allowed himself also] to be baptized into Moses in the cloud and in the sea [they were thus brought under obligation to the Law, to Moses, and to the covenant, consecrated and set apart to the service of God];
3 And all [of them] ate the same spiritual (supernaturally given) food,
4 And they all drank the same spiritual (supernaturally given) drink. For they drank from a spiritual Rock which followed them [produced by the sole power of God Himself without natural instrumentality], and the Rock was Christ.
5 Nevertheless, God was not pleased with the great majority of them, for they were overthrown and strewn down along [the ground] in the wilderness.
6 Now these things are examples (warnings and admonitions) for us not to desire or crave or covet or lust after evil and carnal things as they did.
7 Do not be worshipers of false gods as some of them were, as it is written, The people sat down to eat and drink [the sacrifices offered to the golden calf at Horeb] and rose to sport (to dance and give way to jesting and hilarity).
8 We must not gratify evil desire and indulge in immorality as some of them did—and twenty-three thousand [suddenly] fell dead in a single day!
9 We should not tempt the Lord [try His patience, become a trial to Him, critically appraise Him, and exploit His goodness] as some of them did—and were killed by poisonous serpents;
10 Nor discontentedly complain as some of them did—and were [a]put out of the way entirely by the destroyer (death).
11 Now these things befell them by way of a figure [as an example and warning to us]; they were written to admonish and fit us for right action by good instruction, we in whose days the ages have reached their climax (their consummation and concluding period).
12 Therefore let anyone who thinks he stands [who feels sure that he has a steadfast mind and is standing firm], take heed lest he fall [into sin].
