Should We Fear To Commit Sin?

[Michael The Disciple]

Apostle Paul wrote this to the saints:

10:5 But with many of them God was not well pleased: for they were overthrown in the wilderness.
10:6 Now these things were our examples, to the intent we should not lust after evil things, as they also lusted.
10:7 Neither be ye idolaters, as were some of them; as it is written, The people sat down to eat and drink, and rose up to play.
10:8 Neither let us commit fornication, as some of them committed, and fell in one day three and twenty thousand.
10:9 Neither let us tempt Christ, as some of them also tempted, and were destroyed of serpents.
10:10 Neither murmur ye, as some of them also murmured, and were destroyed of the destroyer.
10:11 Now all these things happened unto them for ensamples: and they are written for our admonition, upon whom the ends of the world are come.

Why dont we hear teaching about this? If one commits a sin they could be destroyed. Seems like Christians should be aware of this.