OP, why not just read the Bible for yourself, and any other religious texts that interest you, such as perhaps the Quran. See what the texts actually say, instead of focusing on what humans say.
It is better to read it for yourself, because there is so much disinformation about it out there, from outright lies to distortions and things taken out of context, and so on. I'm not going to speak for Islam, but I will speak on behalf of my views in regards to Christianity.
In the Bible, the OT and NT together, which are the scriptures of Christianity, it is made super clear, especially in the NT, that the term known by most as "Jews" refers to all disciples of Christ, not a group of people based on ethnicity/genetics and certainly not a religion that actually rejects Jesus. But you will have to look this up for yourself, because trying to explain it usually gets one shouted down, which is ironically unsurprising. I made a post now long ago just giving scripture references on the topic, and now it seems my post was mysteriously deleted. So again, look it up yourself and read the verses for yourself.
Then the Bible spells it out plain as day in Revelation 2:9, which remember, is not referring to an ethnic group, but to those who claim to be disciples of Christ but actually reject Christ's teachings and instead act out with hatred, deceit and other forms of wickedness, hence coming from Satan's influence. This should be completely obvious to anyone when reading that verse, but hey.
There is so much smoke and mirrors all over it that you will simply have to do your own research and reading to understand it fully. But if you do, and then you understand Rev 2:9, then you can see that even God is fully aware that there will be people who self-herald as being His followers, yet who are nothing of the sort, and this certainly includes any cases of so-called Christians who go on murdering sprees and claim that it is "good" and that it is what God wanted. They might fool some people like you, before you read for yourself, but they don't fool God.
And furthermore, you wouldn't have to turn to any of these explanations in the Bible in order to draw the same conclusions for yourself if you simply read the Gospels, as well. If you read the Gospels and form your own understanding of Jesus, the quality of His character is very consistent and straightforward, in that He is very patient, merciful, gentle, loving and so on, and He would have NEVER condoned homicidal rampages in God's name. There is NO way.
I don't, so I don't try to be good or evil.
Moral nihilists like yourself fall into one of two categories:
1. Psychopaths
2. Internet edgelords who think they are very wise and clever, but fall apart real fast in person when asked to explain that they can't know if raping a baby to death is truly wrong or not.
So first you have to determine which category you fall into. Are you a psychopath, or do you acknowledge that we can all inherently know that raping a baby to death is wrong? If the latter, then once you acknowledge that we can know one thing is wrong, then you have established for yourself that humans can inherently know when something is wrong. Then all you need to do is combine with your understanding of Jesus' quality of character (after reading it for yourself), and then combine that with Rev 2:9, and bam congratulations, you understand that God actually is good, some humans tell terrible lies while doing terrible things, and God knows it.
