"I mean, I'm baptized but... I'm not sure I really believe"
Being baptized does not make a person a Christian.
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"Going to church just doesn't interest me, and I don't believe in a God that has churchgoing as a mandate for my life."
Going to church does not make a Christian. However God does command that we are not to forsake the assembling together.
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"I'm not even sure anymore what God I believe in."
Then it sounds like you are not a Christian and possibly never were, if you believe that there are multiple gods.
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"Most of all, I believe in compassion- that is my measure of somebody's morality, and I'm not sure this is really a Christian value at the end of the day."
Then someone has really deceived you on what being a Christian is. One of the central ideals of the Christian faith is compassion. Do Christians fail at compassion? Unfortunately, yes.
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"I'm anti-authoritarian and don't believe in telling people what is the best way to live, because I believe those sorts of questions are best answered by the individual. I'm very unhappy with how Christians have handled the LGBT issue- it goes against my live and let live attitude, and my sensitivity towards my fellow human beings."
This is a very unbiblical viewpoint. God commands us to submit to the authorities place above us (Roman 13). God also tells us that the heart is deceptive and is no basis for morality (Jeremiah 17:9-10).
God commands us to proclaim the gospel to all people. He never commands us to "live and let live", but to warn people of the danger that they are in while they remain in their sin.
Why are you "unhappy" how Christians have handled homosexuality? Because unlike the world, the Christian will not affirm or celebrate someone while they are in rebellion to God in their sin?
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"I don't see many Christians willing to go the extra mile to understand somebody different from them. I see a lot of worship of religious tradition and orthodoxy over caring about real human beings."
Then I wonder about who you have interacted with? And if a Christian is not showing compassion as a regular trend in their life, they are not walking in accordance with the truth of the Bible. The follower of Christianity is not what defines Christianity. God and His inerrant word of the Bible are what defines Christianity.
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"We really don't know God, he's an incomprehensible mystery."
In a way that is true. We don't know the absolute depth of God, because He is infinite and we are not. But we can know God through His Son Jesus Christ, and what He tells us in His inerrant word of the Bible.
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"The classical western theology is absurd, even ridiculous, and can't be taken seriously by intelligent people."
What do you define as "classical western theology"?
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"Believing in an all-powerful benevolent God is simply absurd."
I don't disagree. But that is not the God of the Bible and not the one true and living God. God is not "all-powerful benevolent" while having no other attributes. God is righteous, holy, perfect, eternal, infinite, loving, grace, mercy, omni-present, omniscient, has a righteous wrath against sin, among other attributes.
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"So the way I see it, Christians, as followers of Jesus, should be a humanistic religion more like Confucianism or Taoism, with God and his will left a mystery, and focused on the human predicament."
That is not Jesus of the Bible, it is a false "Jesus" you have created in your imagination to suit your desires. And it sounds like you have been deceived by the social gospel, that Jesus came for simply social justice. That is not the truth. Jesus came to bear witness to the truth: that man is dead in his sins against the holy, righteous and perfect God and yet God in His immeasurable love, came to give mercy, grace and love for all who would abandon their sin and rebellion and trust in Him. Taking care of the poor and needy is important and it is a side effect of the gospel of Jesus Christ, but it is not the gospel itself.
I would recommend you read and study the Bible and humbly ask God to reveal the truth to you, because from what you wrote, you appear to be greatly deceived on the truth of God, the Bible and Christianity. I don't truly know your heart, but it sounds as if you never were a Christian.