tobechi74:
Every thing must not be mentioned in the Bible

If you truly meant what you say, then I think your Christianity should be questioned, or you don't believe that the bible is the word of God and Gods heart beat to man.
Carefully check out the following scriptures.

1. 2 Timothy 3:16_17
All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, 17 so that the servant of God[a] may be thoroughly equipped for every good work.

2. 2 peter 1:3
as His divine power has given to us all things that pertain to life and godliness, through the knowledge of Him who called us by glory and virtue.

3. Deuteronomy 29:29
“The secret things belong to the LORD our God, but the things which are revealed and disclosed belong to us and to our children forever, so that we may do all of the words of this law.