If Christ provides only a part of our salvation, leaving us to provide the rest, then we are still hopeless under the load of sin. For no matter how small the gap which must be bridged before salvation can be attained, the awakened conscience sees clearly that our wretched attempt at goodness is insufficient even to bridge that gap. The guilty soul enters again into the hopeless reckoning with God, to determine whether we have really done our part.
—J. Gresham Machen, Christianity and Liberalism, New Edition. (Grand Rapids; Cambridge, U.K.: William B. Eerdmans Publishing Company, 2009), 21. (HT: Jack Miller)
Calvin: “that the kingdom of heaven is not the hire of servants, but the inheritance of sons, (Ephesians 1:18;) an inheritance obtained by those only whom the Lord has adopted as sons, and obtained for no other cause than this adoption, “The son of the bond-women shall not be heir with the son of the free-woman,” (Galatians 4:30.) And hence in those very passages in which the Holy Spirit promises eternal glory as the reward of works, by expressly calling it an inheritance, he demonstrates that it comes to us from some other quarter.”