Why Does the Church Condemn Non-Catholics?

The Church condemns those who are not Catholic because they reject the true Gospel which is taught and interpreted by the Church alone which is guided by the Holy Spirit [Jn. xiv. 26]. St. Paul gives us this command: "But though we, or an angel from heaven, preach a gospel to you besides that which we have preached to you, let him be anathema. As we said before, so now I say again: If any one preach to you a gospel, besides that which you have received, let him be anathema [Gal. i. 8-9]." Paul is clear and even reiterates, showing the significance of his command. Paul also says, "A man that is a heretic, after the first and second admonition, avoid: Knowing that he, that is such an one, is subverted, and sinneth, being condemned by his own judgment [Tit. iii. 10-11]." An our Lord and God Jesus Christ says, "And if he will not hear thee, take with thee one or two more: that in the mouth of two or three witnesses every word may stand. And if he will not hear them: tell the church. And if he will not hear the church, let him be to thee as the heathen and publican [Mt. xviii. 16-17]." Those who are not subject to truth ought to be treated so. Those adherents to false Gospels are to be treated as heathens and publicans, for they do not listen to the Church, instituted by Christ, and has such authority.