(b) The children born are in serious danger of being deprived of the faith (i.e., of not being brought up as Catholics), or of having their faith weakened by the example of parents who do not agree in the matter of religion. If the non-Catholic or fallen-away Catholic interferes with the religion of the children, their baptism, religious education, attendance at church, etc., will be forbidden or impeded; if that party does not interfere, there will be at least the example during impressionable years of one parent who does not accept the Catholic faith or who disregards its requirements. Statistics indicate that one of the chief sources of leakage in the Church today is mixed marriages. 877. Dangerous marriages are also forbidden by the law of the Church. (a) Lack of baptism in the non-Catholic party causes the diriment impediment of disparity of worship (Canon 1070); (b) membership of the non-Catholic party in an heretical or schismatical sect causes the prohibitive impediment of mixed religion (Canon 1060); (c) unworthiness of one of the parties, on account of notorious apostasy or affiliation with forbidden societies (see 945 sqq.), prevents the pastor from assisting at the marriage without permission from the Ordinary (Canon 1065). 878. No one may enter into any of the dangerous marriages here considered, unless the requirements of the natural and ecclesiastical laws be complied with. (a) The natural law requires under pain of grave sin that the danger of perversion be removed, that no non-Catholic ceremony take place, and that the Catholic spouse work prudently for the conversion of the other party. (b) The ecclesiastical law requires under grave sin that guarantees be given that the requirements of the natural law shall be fulfilled (Canons 1061, 1071); that there be grave and urgent reasons for the marriage (ibid.); that dispensations from the impediments be obtained, or permission, in the case of unworthiness of one of the parties, to assist at the marriage be granted by the Ordinary (Canons 1036, 1065). 879. The canonical consequences of dangerous marriages illegally contracted are as follows: (a) Those who knowingly contract a mixed marriage without dispensation are _ipso facto_ excluded from legitimate ecclesiastical acts, (e.g., the office of godparent), and from the use of sacramentals, until a dispensation has been obtained from the Ordinary (Canon 2375). Marriage contracted with the impediment of disparity of worship is invalid, whether the parties are in ignorance or not (Canon 1070, Sec.16). (b) Catholics who enter into marriage before a non-Catholic minister acting in a religious capacity or who contract marriage with the implicit or explicit understanding that any or all of the children will be educated outside the Church incur excommunication _latae sententiae_ reserved to the Ordinary (Canon 2319).