885. Communication with unbelievers that is a remote occasion of sin, is not sinful, for “otherwise one must needs go out of this world” (I Cor., v. 9). On the contrary, reasons of justice or charity frequently make it necessary and commendable to have friendly dealings with those of other or no religious conviction. (a) Reasons of justice. It is necessary to cooperate with non-Catholic fellow-citizens in what pertains to the welfare of our common country, state, city, and neighborhood; to be just and fair in business relations with those outside the Church, etc. (b) Reasons of charity. Catholics should be courteous and kind to all (Heb., xii. 14), and be willing to assist, temporarily and spiritually, those outside the Church. Thus, St. Paul, without sacrificing principle or doctrine, made himself all things to all men, in order to gain all (I Cor., ix. 19). Indeed, the mission of the Church would suffer, if Catholics today kept aloof from all that goes on about them. The Church must teach, by example as well as precept, must be a salt, a light, a leaven, an example of the Gospel in practice; and surely this ministry will be weakened if her children aim at complete isolation and exclusivism. 886. Societies that are purely civil or profane--e.g., social clubs, charitable organizations, temperance societies, labor unions, that are not identified with any church and are neutral in religion--may be dangerous to faith. (a) There may be danger on account of the membership, even when the nature of the society is purely indifferent or good. Example: It would be dangerous to faith to join a convivial society whose members were mostly aggressive infidels, even though the purpose of the organization was only recreation. (b) There may be danger to faith on account of certain methods or principles of the society. Example: A Boys’ or Girls’ Club whose purpose is to train young people for good citizenship is dangerous to faith, if it acts as though the natural virtues were sufficient, or as though moral education belonged to itself exclusively or principally. 887. The Sin of Blasphemy.--So far we have spoken of the sins of unbelief that are contrary to the internal act of faith. We now come to the sins that are contrary to the external act, or profession of faith. These sins are of two kinds: (a) The less serious sin is that of ordinary denial of the faith, that is, the assertion that some article of faith is false, or that some contrary error is true. This sin will be treated below in 913 sqq. on the commandments of faith. (b) The more serious sin is blasphemy, that is, the denial to God of something that is His; or the ascription to God of what does not belong to Him. Of this sin we shall speak now.