God's covenants clearly have conditions, as we have seen over the past few days. The question before us now, however, is what happens when these conditions are met and what happens when they are not met? The answer is that meeting the conditions perfectly leads to eternal life, and, in the final analysis, we can only do this by trusting in Christ Jesus alone, who alone has kept the covenant perfectly (2 Cor. 5:21).
Although meeting the covenant conditions leads ultimately to eternal life—via the faith-alone imputation of the merit of Christ, the perfect covenant-keeper—there are also earthly blessings for keeping covenant that anticipate the life of the world to come. This is particularly evident under the Mosaic covenant, which was the foundational covenant for the prophets' ministry. In fact, the blessings that the prophets announced to ancient Israel were the blessings promised to those who kept the Mosaic law. These blessings are revealed most clearly in Leviticus 26:1–13 and Deuteronomy 28:1–14.
The two lists differ slightly, but the teaching of both texts is the same. God promised the Israelites that if they were to keep the covenant, they would experience food harvests so great that they would be unable to gather everything in before it was time to sow the seed once more (Lev. 26:3–5). Faithful Israel would enjoy peace, victory over her enemies, and fruitfulness in the womb (vv. 6–10). The blessings build to the crescendo of the greatest covenant benefit of all—the presence of God Himself with His people (vv. 11–13).
When the prophets announced blessings to Israelites who persevered in covenant obedience or returned to the Lord after grossly breaking His law, they promised the very blessings we have just listed. Jeremiah 23:1–4, for example, promises the faithful remnant of Israel that it will experience great fruitfulness. Ezekiel 36:22–32 looks forward to the Spirit of God dwelling within the hearts of His children.
Ancient Israel was not to look at keeping God's covenant as a means to earn their salvation. Thus, for the old covenant people, faithfulness did not mean perfect obedience, which is impossible for sinners. They were to strive to obey, repent when they failed, and look for the Messiah to earn salvation for them by His following the law perfectly (Gen. 3:14–15; Lev. 18:5; Deut. 18:15). But as they conformed, generally speaking, to God's law, they enjoyed a foretaste of eternal life in the new heaven and earth.