Working for a Living: Can You Earn Your Keep?

The law was given after after the redemption from Egypt had been accomplished, and the people had already entered upon the enjoyment of many blessings of the berith.¹  Particularly their taking possession of the promised land could not have been made dependent on previous observance of the law, for during their journey in the wilderness many of its prescripts could not be observed.  It is plain, then, that law-keeping did not figure at that juncture as the meritorious ground of life-inheritance.  The latter is based on grace alone, no less emphatically than Paul himself places salvation on that ground.  But while this is so, it might still be objected, that law-observance, if not the ground for receiving, is yet made the ground for retention of the privileges inherited.  Here it can not, of course, be denied that a real connection exists.  But the Judaizers went wrong in inferring that the connection must be meritorious, that, if Israel keeps the cherished gifts of Jehovah through observance of His law, this must be so, because in strict justice they had earned them.  The connection is of a totally different kind.  It belongs not to the legal sphere of merit, but to the symbolico-typical sphere of appropriateness of expression....Although the demands of the law were at various times imperfectly complied with, nevertheless for a long time Israel remained in possession of the favor of God.  And even when the people as a whole become apostate, and go into exile, Jehovah does not on that account suffer the berith to fail.  After due chastisement and repentance He takes Israel back into favor.  This is the most convincing  proof that law-observance is not the meritorious ground of blessedness.  God in such cases simply repeats what He did at the beginning, viz., receive Israel into favor on the principle of free grace.

Geerhardus Vos, Biblical Theology: Old and New Testaments, 142-144

¹ "Covenant" here and following.