Religious reform has nothing to do with humanism, it can be said that it is just the opposite. You must first know why you want to carry out the religious reform. In fact, religious reform can't be called religious reform, just like Christianity is going to change. In fact, it should be said that it is a religious reform movement. You have to know what Christianity is first.
According to God's direct revelation in the Bible, after God created mankind, mankind fell into sin (Adam and Eve ate the forbidden fruit and violated the Lord's command. Descendants have multiplied into human beings, but human beings are still trapped in sin and cannot meet the standards of God. The righteous God will judge mankind, but God will forgive mankind because of his kindness. God first chose Israel as his people, and promised them that a Messiah would be born in the future, to save them from foreign oppression (which was caused by Israel's betrayal of God in the future) and to save mankind from sin. This is all god's arrangement. Sure enough, Jesus was born in Judea under the Roman Empire. He preached everywhere, calling on Jews to repent and telling the essence of the laws that God made for Israel in the past. It turns out that God wants human beings to love God and love others as themselves, and anyone who believes in him can live a rich life from God. It is a kind of life that should have been gained but lost because of Adam and Eve's crime, and it is a kind of eternal life. He also performed miracles extensively, suggesting in various ways that he was the one promised by God, and even suggesting that he was God (the manifestation of God in the body). He also said that he would die at the hands of sacrifices, but he would be resurrected, and he would come again for the last judgment (the judgment of sinners who refused to repent, and they would go to hell). Sure enough, his fame attracted the attention and jealousy of the Jewish sacrificial groups at that time. They threatened the then Roman governor Pilate with riots to execute Jesus, whip him and crucify him, but he came back to life on the third day. But this just fulfilled God's promise. It turned out that God predicted this in the Old Testament of Israel, and it was the death of Jesus that saved mankind. He paid the ransom instead of human beings, because the result of the crime was death. His resurrection proved that he was a god and he had the ability to bring his promised life to believers.
Therefore, man is depraved, evil in nature and in need of redemption. With his limited and degenerate rationality, it is impossible to truly realize self-salvation in human society and solve various problems in human nature. This is largely hidden in Catholicism, in which Catholicism has greatly improved human rationality, and has not really understood the Bible and seen the correct information conveyed in it. But at that time, those religious reformers saw that Martin Luther, John Calvin and so on. They all returned to the Bible and realized the true content of the Bible and the mistakes of the church at that time, so they reformed their religion and called on believers to return to the original purest Christian faith.