I’m trying to gather information from the Old Testament (and maybe the new) on this theory: That the Lord commands / wants his followers to gain knowledge. That there are, in fact, mysteries in life; we just have to solve them. I know this is somehow a pilar of gnosticism, and I’m wondering if there’s anything in the bible to back it up, or to specifically refute it (I’m thinking for the latter case G-d’s rebuke against Jobe trying to fathom him in the end of the tale of Jobe.)
A few “positives” from the OT:
Job 28:17-19: “The gold and the crystal cannot equal it: and the exchange of it shall not be for jewels of fine gold. No mention shall be made of coral, or of pearls: for the price of wisdom is above rubies. The topaz of Ethiopia shall not equal it, neither shall it be valued with pure gold.”
Psalm 51:6: “Behold, thou desirest truth in the inward parts: and in the hidden part thou shalt make me to know wisdom.”
Proverbs 2 - forgive me for not quoting it in its entirety. 
Proverbs 4:5-9: "Get wisdom, get understanding: forget it not; neither decline from the words of my mouth. Forsake her not, and she shall preserve thee: love her, and she shall keep thee. Wisdom is the principal thing; therefore get wisdom: and with all thy getting get understanding. Exalt her, and she shall promote thee: she shall bring thee to honour, when thou dost embrace her. She shall give to thine head an ornament of grace: a crown of glory shall she deliver to thee. "
Proverbs 7:4: “Say unto wisdom, Thou art my sister; and call understanding thy kinswoman:”