The Bible taken as a whole shows that God is the ultimate source of all goodness and truth and indeed that he is the epitome of those things. It therefore can be said that not only does God love, but “God is love” (1 John 4:8,16), not only does God speak only the truth, but God is “the truth” (John 14:6). This is typically referred to be philosophers and theologians as the divine simplicity of God. I love how Got Questions puts it when discussing the love of God : “God’s love is in no sense in conflict with His holiness, righteousness, justice, or even His wrath. All of God’s attributes are in perfect harmony. Everything God does is loving, just as everything He does is just and right. God is the perfect example of true love.”— https://www.gotquestions.org/God-is-love.html
One of my favorite verses that talks about the perfect nature of God is 1 John 1:5 “God is light, and in Him is no darkness at all.” I also love James 1:17 “Every good gift and every perfect gift is from above, and cometh down from the Father of lights, with whom is no variableness, neither shadow of turning.” God is by definition the embodiment of light, there is no darkness in him at all. There is no variation or shadow. Everything he does is right because that is his divine and perfect nature. “God cannot be tempted by evil, and He Himself does not tempt anyone” (James 1:13). Similarly, it is “impossible for God to lie” and this is an “immutable thing[].” (Heb 6:18). Everything that he says is by definition and necessity true.
All of this starts from the foundational truth that God is the sole creator of everyone and everything that exists in the universe. If you get this wrong, then you are going to get the relationship between God and his attributes like love and justice backwards. You are going to conclude as Mormons do that God is a being that is governed by some external and objective standards of “love” or “truth” or justice.” But that’s not what the bible teaches about God’s nature.
Col 1 speaks of Christ’s role in creation and makes clear that he is the maker of everything that exists and that everything depends on his will to exist. Christ “created: things in heaven and on earth, visible and invisible, whether thrones or powers or rulers or authorities; all things have been created through him and for him. He is before all things, and in him all things hold together.” Heb 11 :3 similarly explains that God created the universe by his command such that “what is seen was not made out of things that are visible.” Paul put it particularly well in Romans 11:36 – “For from Him, and through Him, and to Him are all things. To Him be the glory forever. Amen.” – and in Acts 17:28 where he explains that “for in Him we live and move and exist”
Because God is the supreme creator of all things, there can be no higher external standard governing God. Everything that exists must exist thanks to and with reference to God’s perfect attributes and nature.
As creations of God, we simply have no way of evaluating the actions of our creator and condemning him. I already mentioned Paul’s powerful words in Romans 9: “One of you will say to me: “Then why does God still blame us? For who is able to resist his will?” But who are you, a human being, to talk back to God? “Shall what is formed say to the one who formed it, ‘Why did you make me like this?’” Does not the potter have the right to make out of the same lump of clay some pottery for special purposes and some for common use?”
In addition, I would point to the Book of Job where Job demands an explanation from God for his suffering and asks to know how God can allow it and yet be just. God appears to him in the whirlwind and speaks about his vast and infinite power. He explains that Job was not there when he lay the foundation of the world and has no idea about the extent of the glory of God. God emphasizes “Who has a claim against me that I must pay? Everything under heaven belongs to me.” Job’s response is telling, he exclaims “Surely I spoke of things I did not understand, things too wonderful for me to know” and he repents in dust and ashes. This is such a powerful insight into how infinitely beyond us God truly is.