Understanding Biblical and Church history will help us learn and avoid making mistakes.
Romans 15:4 says, “For whatever things were written before were written for our learning, that we through the patience and comfort of the Scriptures might have hope.”

1 Corinthians 10:11 also says, “Now all these things happened to them as examples, and they were written for our admonition, upon whom the ends of the ages have come.”

Remembering the past gives strength.
Deuteronomy 32:7-8 says, “Remember the days of old, consider the years of many generations. Ask your father, and he will show you; your elders, and they will tell you: when the Most High divided their inheritance to the nations, when He separated the sons of Adam, He set the boundaries of the peoples according to the number of the children of Israel.”

We should teach our children what God has done in our lives and in Bible times.
Deuteronomy 4:9-10 says, “Only take heed to yourself, and diligently keep yourself, lest you forget the things your eyes have seen, and lest they depart from your heart all the days of your life. And teach them to your children and your grandchildren, especially concerning the day you stood before the Lord your God in Horeb, when the Lord said to me, ‘Gather the people to Me, and I will let them hear My words, that they may learn to fear Me all the days they live on the earth, and that they may teach their children.’”

History often repeats itself. Remember there is nothing new under the sun.
Ecclesiastes 1:9-10 says, “That which has been is what will be, that which is done is what will be done, and there is nothing new under the sun. Is there anything of which it may be said, ‘See, this is new’? It has already been in ancient times before us.”