We have no problem accepting from God the good things He tells us about Himself. "God is love" is pleasant. That He is the Creator is good. Most of us like His attributes like omnipotence, omniscience, and omnipresence. That He is everlasting is fine with us, even if it isn't entirely comprehensible. We really like His mercy and grace. We are fairly happy with lots of the things we know about God. Most of us, however, draw the line at some point.
We believe that the Bible is "God-breathed", that God is the source of the Bible, having "breathed" it into the writers who used their own divinely-superintended words to write what God wanted to express. We claim it, then, to be "God's Word". Now, to be fair, much of it is not precisely God's words. That is, it isn't a quote from God. However, there are passages that are quotes from God. One of these is found in Isaiah.
"I am the LORD, and there is no other, besides Me there is no God; I equip you, though you do not know Me, that people may know, from the rising of the sun and from the west, that there is none besides Me; I am the LORD, and there is no other. I form light and create darkness, I make well-being and create calamity, I am the LORD, who does all these things." (Isa 45:5-7)This isn't merely "God-breathed" inspiration. It is a direct quote. And what does God claim about Himself here? Sure, He claims to "equip" those who do not know Him, requiring His involvement in their lives without their permission. But that's less offensive than His next claim. "I form light and create darkness, I make well-being and create calamity." We're fine with the light and well-being He makes, but how about His claim that He creates darkness and calamity? (The King James says "evil", by which we understand Him to mean "unpleasant circumstances" as opposed to "moral evil".) Many of us will attribute to God the good things that happen in our lives. How many of us will allow that the trials and tragedies also come from Him?
We know that God is gracious, loving, and merciful, but how about the biblical claim that it is God's will that He demonstrate His wrath and power on vessels of wrath prepared for destruction (Rom 9:22)? We'll skip right over that as quickly as we can to get to the part where He makes known "the riches of His glory for vessels of mercy" (Rom 9:23) because that part we like.
We like the part about how God "desires all people to be saved and to come to the knowledge of the truth" (1 Tim 2:4), so it's hard to fathom the biblical statement that "God gave them a spirit of stupor, eyes that would not see and ears that would not hear, down to this very day." (Rom 11:8) Similarly, we have to walk carefully when it says "The LORD hardened Pharaoh's heart" (Exo 10:20, 10:27; 11:10) and claims that God raised Pharaoh up in order to demonstrate that He has mercy on whomever He wills and hardens whomever He wills (Rom 9:17-18).
Some of what God says about Himself we take lightly. Much of it we like. But there are things that God's Word says about the nature of God that runs so sharply against our human sensibilities that we are often likely to toss them out entirely. "Can't mean that." "God is not like that." "A loving God would never do that." Except it is what it says and it is, by virtue of it being God's Word, what He claims about Himself.
A view of God that dismisses God's own presentation of Himself is not a view of God; it is idolatry. When we read that "God is love", we cannot dismiss the rest of what He says about Himself because "love is like a warm puppy and He would never do that" as a replacement of what He says. Anything that replaces the true God is an idol. And we are not unclear on God's' view of idolatry.