Exodus 17:14 And the LORD said unto Moses, Write this for a memorial in a book, and rehearse it in the ears of Joshua: for I will utterly put out the remembrance of Amalek from under heaven.
This verse is taken from the story of Moses on the mountain Aaron and Hur, and Joshua in the valley with the army. God gave a great victory to the armies because of Moses being on the mountain, not because of Joshua in the valley with the army. The victory came from God! Joshua did not know what was happening on the mountain, so God had Moses write in a book, and rehearse it (the story) in the ears of Joshua.
God was telling Moses to preserve, in writing, the working of God in his life, and then to teach others (Joshua) what God had done. The purpose was to build Joshua's faith and to prepare him to one day be the next leader.
It is the responsibility of leaders to write and publish what God has done for them and then to teach those great truths to others. Dr. Brandenburg has devoted much of his ministry to writing and publishing materials to help Believers in their walk WITH God and their work FOR God. These are available as written materials as well as recorded messages.