Noah was commanded by God to preach repentance to the people. He was a prophet and authorized to speak for God. When the people chose to ignore the teachings of their prophet, God commanded Noah to build an ark.

Today, we are still commanded to listen to prophets, as God’s children have from the beginning of time, and we are still commanded to repent and to obey the commandments. Those are doctrines. We do not have a responsibility to build an ark. Building an ark was a policy meant to meet the needs of the time, not an eternal principle.

God’s church operates on a combination of policy and doctrine. Doctrines are eternal laws ordained by God from the beginning of time and will always be true. Policies merely meet the needs of a given time and have no eternal impact. Both are essential to the operation of the church, since policies make certain there is order and that no one wanders off into inappropriate actions. However, policies change the meet the needs. Arks were a necessity for Noah’s time, but not for ours.

A Mormon apostle taught:

“There are principles of the gospel underlying every phase of Church administration. These are not explained in the handbooks. They are found in the scriptures. They are the substance of and the purpose for the revelations.

Procedures, programs, the administrative policies, even some patterns of organization are subject to change. We are quite free, indeed, quite obliged to alter them from time to time. But the principles, the doctrines, never change.

If you over-emphasize programs and procedures that can change, and will change, and must change, and do not understand the fundamental principles of the gospel, which never change, you can be misled.” Principles, Elder Boyd K. Packer Of the Quorum of the Twelve

The doctrines are the foundation of the gospel. They decide how eternity works, what we have to do to achieve eternal exaltation, how God organized the world. These things matter eternally and they can never change. God will never decide we don’t need to pray or that it is okay to ignore those in need. He will never alter the structure of the family. These are doctrines. The nature of God is eternal—it is a fact and will not change. However, the number of meetings held on Sunday, the name of the class eight-year-olds attend, and whether or not children can receive candy in class are just practices. They change all the time.

Sometimes it can be easy to confuse policy and doctrine. After all, building the ark was a direct commandment from God and saved quite a number of human and animal lives and kept the world from coming to an end. It was obviously very important. However, it was not a commandment meant to last forever—we don’t all have to build arks. It was a policy designed to meet the immediate needs of the people. Peter was instructed to take the gospel to all people, not just the Jews. That was a change in policy, not doctrine. We know from studying eternal truths that eventually:

 10 That at the name of Jesus every knee should bow, of things in heaven, and things in earth, and things under the earth;

11 And that every tongue should confess that Jesus Christ is Lord, to the glory of God the Father (Philippians 2.)

This tells us that the decision to take the gospel only to the Jews for a while was merely a policy, not meant to last forever. Eternal truths are of value to every generation.

When evaluating how the church operates, it is essential to known what is doctrine and what is policy. It requires careful study of both the doctrine or policy and the surrounding issues to understand which an item is. We must look to the history, the scriptures, the teachings of the prophets, and the results of our personal prayers.