ith the fulness of God because
united to God; the saints receive of the fulness of Christ, because
united to Christ. "I in them, and Thou in Me." Only here is the
difference. Christ's union with His Father was personal, infinite, and
substantial, and therefore the communications were answerable, "For God
gave not the Spirit by measure unto Him." But the saints' union with
Christ, being of an inferior nature; their communications also are
proportional; yet such as serve poor creatures to all blessed saving
purposes. And therefore with Paul, labour to "be found in Christ," that
so you may know experimentally the power of His resurrection, and the
fellowship of His sufferings. All the power and virtue that are in Jesus
Christ, are only for them that are in Him, as the branch in the root, as
the members in the body.

Christ is called the covenant of God. "I will give thee for a covenant
of the people." As Calvin well expounds it, _sponsor foederis_, the
surety or undertaker of the covenant, of that second new covenant,
between God and His people, not the Jews only, but the Gentiles also. A
surety on both sides: the surety of God's covenant to them; "For all the
promises of God are in Him, yea, and in Him, Amen." He sees them all
made good to the heirs of promise. And Christ again is the surety of
their covenant unto God; for He undertakes to make good all their
covenants, and vows, and promises unto God. "Those that Thou gavest Me,
I have kept," saith Christ. "And I live (saith Paul), yet not I, but
Christ liveth in me." So that it is Christ who makes the covenant good
on both sides, as God's to His people, so His people's to God; and so it
follows in that place of Isaiah, "I have given thee for a covenant to
the people, to establish the earth;" establishment must come from
Christ, the undertaker, the surety of the covenant; as He paid the debt
for the time past, so He must see the articles of the covenant kept for
the time to come. For want of such an undertaker or surety, the first
covenant miscarried: It was between God and the creature, without a
mediator; and so the creature changing, the covenant was dissolved; but
the second, God meant should not miscarry, and therefore puts it into
sure hands; "I have laid help upon One that is mighty," speaking of
Christ, and "I will give Thee for a covenant to the people." God hath
furnished Christ wherewithal to be a surety; to make good His covenant
to His people, and their cove