Question. You say, “But how shall I come to know whether I am almost or altogether a Christian? If a man may go so far, and yet miscarry, how shall I know when my foundation is right—when I am a Christian indeed?”
Answer. The altogether Christian closes with, and accepts of Christ upon Gospel terms. True union makes a true Christian: many close with Christ, but it is upon their own terms; they take him and own him, but not as God offers him. The terms upon which God in the gospel offers Christ, are, that we shall accept of a broken Christ with a broken heart, and yet a whole Christ with the whole heart. A broken Christ with a broken heart, as a witness of our humility; a whole Christ with a whole heart, as a witness of our sincerity. A broken Christ respects his suffering for sin; a broken heart respects our sense of sin; a whole Christ includes all his offices; a whole heart includes all our faculties. Christ is a King, Priest, and Prophet, and all as Mediator. Without any one of these offices, the work of salvation could not have been completed. As a Priest, he redeems us; as a Prophet, he instructs us; as a King, he sanctifies and saves us. Therefore, the apostle says, “He is made to us a God of wisdom, righteousness, sanctification, and redemption.” Righteousness and redemption flow from him, as a Priest, wisdom, as a Prophet, sanctification, as a King.
Now many embrace Christ as a Priest, but yet they own him not as a King and Prophet; they like to share in his righteousness, but not to partake of his holiness; they would be redeemed by him, but they would not submit to him; they would be saved by his blood, but not submit to his power. Many love the privileges of the gospel, but not the duties of the gospel. Now these are but almost Christians, not withstanding their close with Christ; for it is upon their own terms, but not upon God’s. The offices of Christ may be distinguished, but they can never be divided. But the true Christian owns Christ in all his offices: he doth not only close with him as Jesus, but as Lord Jesus: he says with Thomas, “My Lord, and my God.” He doth not only believe in the merit of his death, but also conforms to the manner of his life. As he believes in him, so he lives to him: he takes him for his wisdom, as well as for his righteousness; for his sanctification, as well as his redemption
– Matthew Mead