3. In [keeping] his institutions, or matter and manner of his worship. Christ marrying his church to himself, taking it to that relation, still expresseth the main of their chaste and choice affections to him to lie in their keeping his institutions and his worship according to his appointment. The breach of this he calls “adultery” everywhere, and “whoredom.” He is a “jealous God;” and he gives himself that title only in respect of his institutions. And the whole apostasy of the Christian church unto false worship is called Rev. xvii. 5.“fornication;” and the church that leads the others to false worship, the “mother of harlots.” On this account, those believers who really attend to communion with Jesus Christ, do labour to keep their hearts chaste to him in his ordinances, institutions, and worship; and that two ways:—