You are commanded to teach one another the doctrine of the kingdom… that you may be instructed more perfectly in theory, in principle, in doctrine, in the law of the gospel, in all things that pertain unto the kingdom of God, that are expedient for you to understand:

What are these things?

• things both in heaven and in the earth, and under the earth
• things which have been, things which are, things which must shortly come to pass
• things which are at home, things which are abroad
• the wars and the perplexities of the nations
• the judgments which are on the land
• a knowledge also of countries and of kingdoms.

Why should we learn these things?

• That ye may be prepared in all things.

Then what do we do?

• …and it becometh every man who hath been warned to warn his neighbor. Therefore, they are left without excuse, and their sins are upon their own heads.

Abide ye in the liberty wherewith ye are made free; entangle not yourselves in sin, but let your hands be clean, until the Lord comes.

Be as a Watchman on the tower (D&C 101).