Jeremiah 31

Jer. 31:33. "But this shall be the covenant that I will make with the house of Israel; after those days, saith the Lord, I will put my law in their inward parts, and write it in their hearts, and will be their God, and they shall be my people." I think the difference here pointed out between these two covenants, lies plainly here, that in the old covenant God promised to be their God upon condition of hearty obedience; obedience was stipulated as a condition, but not promised. But in the new covenant, this hearty obedience is promised if a man be but of the house of Israel, as by faith he becomes so. God promises expressly in this new dispensation that he shall perform a hearty obedience, and so have God for his God. That old covenant they broke, as it is said in the foregoing verse. The house of Israel, these were called so under the Old Testament, could break that; but the new covenant is such as cannot be broken by the spiritual house of Israel, because obedience is one thing that God engages and promises; and therefore this is called an everlasting covenant upon this account, as is plain from Jeremiah 32:40. It is true the true saints, in the Old Testament, could not fall away any more than they can now, but they were not the Old Testament Israel; and, though God had engaged in his covenant with Christ that they should not fall away, yet he had not expressly revealed that to them. God had not in those days so plainly revealed the primary and fundamental condition of the covenant of grace, viz. faith; but insisted more upon the secondary condition, universal and persevering obedience, the genuine and certain fruit of faith.

Ezekial

Eze. 1