Will Catholics go to hell?
"Therefore you are inexcusable, O man, whoever you are who judge, for in whatever you judge another you condemn yourself; for you who judge practice the same things. But we know that the judgment of God is according to truth against those who practice such things. And do you think this, O man, you who judge those practicing such things, and doing the same, that you will escape the judgment of God? Or do you despise the riches of His goodness, forbearance, and longsuffering, not knowing that the goodness of God leads you to repentance? But in accordance with your hardness and your impenitent heart you are treasuring up for yourself wrath in the day of wrath and revelation of the righteous judgment of God, who "will render to each one according to his deeds": eternal life to those who by patient continuance in doing good seek for glory, honor, and immortality; but to those who are self-seeking and do not obey the truth, but obey unrighteousness--indignation and wrath, tribulation and anguish, on every soul of man who does evil, of the Jew first and also of the Greek; but glory, honor, and peace to everyone who works what is good, to the Jew first and also to the Greek. For there is no partiality with God" (Romans 2:1-11).
Anyone not doing the will of God will face the wrath and punishment of God. There is no religion that will protect a person from this simple fact. No membership in any religion is a guarantee of escaping Hell and entering Heaven. "Let us therefore be diligent to enter that rest [heaven], lest anyone fall according to the same example of disobedience" (Hebrews 4:11).
So are you saying not to judge?
We judge in accordance with God's will. "Do not judge according to appearance, but judge with righteous judgment" (John 7:24). We are not left blind. God has told us how He will judge. It matters not if I like or dislike Catholicism. The true question is: "Are Catholics obeying God's will?" The result of that determination is also up to God, though He has told us how He will judge: the disobedient will end up in eternal punishment.
Christians must avoid placing themselves in God's judgment seat. I cannot make the final determination of who will go to heaven or hell. Even Michael the Archangel said in a dispute with Satan, "The Lord rebuke you!" (Jude 9). If there is someone we know would end up in Hell, it would be Satan. But Michael would not place himself in the position of acting as God. However, notice that Michael did make a determination or judgment. He did call on God to rebuke Satan. Hence, Michael did determine that Satan was in the wrong.