Two attributes of God that should reassure those who love him.
Omniscience
Quoting from Louis Berkhof at Ordinary Pastor:
The knowledge of God is not only perfect in kind, but also in its inclusiveness. It is called omniscience, because it is all-comprehensive. In order to promote a proper estimate of it, we may particularize as follows: God knows Himself and in Himself all things that come from Him (internal knowledge).
Yep, all of God’s knowledge is from himself.
Immutability
From R. C. Sproul, Jr. at Ligonier Ministries Blog:
This attribute is that which enables us to depend on God to be God. It is why we can be certain that every excellency, every perfection, indeed every promise of God is utterly inviolable. He shall not be moved.