II.  That all church members ought to be sincere-hearted believers appears by the high titles which the Lord Jesus gives unto them in Scripture:  they are described to be like the king’s daughter, all glorious within.  They are called saints, holy brethren, and beloved, elect, dear children of God, the spouse of Christ, a holy temple of God, lively stones, built up a spiritual house, a holy priesthood, and the Lord’s sealed ones.  Now such honorable titles belong not unto mere formal professors, but only unto the real members of Christ:  not unto those that have a name only; but to such as are so indeed and in truth.

III.  A third reason is taken from the ends of God in instituting and appointing churches.  They are said to be built by the Spirit for God, i.e. for God to dwell and walk in them, to repose himself in them, as in his holy garden, house, and temple.  They are designed for promoting his glory in the world, to distinguish his people from others; that they should be to the praise of his glorious grace, and be the living witnesses to his name, truths, and ways; that they should be the habitations of beauty and glory, of fame and renown in the world, and be the light thereof; and that with one heart and mouth they should glorify God.  Believers are united into a church capacity for their spiritual profit and advantage, that God may there give them his love, and communicate his grace, truths, and counsels to them, as to his avowed household and family Christ walks there, and God the Father dwells there, and the Holy Spirit speaks to them in a special and frequent manner to distribute liberally of their love and fulness.  They are formed and set up by Jesus Christ to be the only seats and subjects of his laws, ordinances, power, and authority, that they might receive, obey, and observe his laws, declare before the world their owning of him for their Lord, by their open and public profession of, and subjection unto him, as such; and that, by their regular and distinct following of him in their united church state, they might manifest to all men, that they are his subjects and disciples, that they have chosen him for their Lord and King, and his law for the rule of their faith and obedience; that they are not their own, but his; and that they have reposed themselves in him, as their happiness and eternal blessedness; that they are called out of the world and set apart by his grace for himself, to live unto him; and that they have taken upon themselves his holy yoke, and the observation of all his laws.  God has united believers into churches, that by his Spirit and ministers he may feed and nourish them there as his flock, water them as his garden, support them as his house, and order and govern them as his family and household.