Read Hebrews 3:12-19. Why was Israel unable to enter into the promised rest?

 The sad story is that those who were delivered from Egypt were unable to enter into the rest that God had promised them. When Israel arrived at Kadesh Barnea, at the border of the Promised Land, they lacked the faith that they needed. Numbers 13 and 14 explain that the Israelite spies “brought to the people of Israel a bad report of the land” (Num. 13:32, ESV). They affirmed that the land was good, but they warned that the inhabitants were strong and that the cities fortified, and that they would not be able to conquer it.

 Joshua and Caleb agreed that the land was good and did not dispute the fact that people there were strong and the cities fortified. But they said that God was with them and that He would bring them into the land (Num. 14:7-9). Yet, the people who saw God destroy Egypt through plagues (Exodus 7-12), annihilate Pharaoh’s army in the Red Sea (Exodus 14), provide bread from heaven (Exodus 16) and water from the rock (Exodus 17), as well as manifest His continuing presence and guidance through the cloud (Exod. 40:36-38) — they failed to trust in Him now. It is a tragic irony that the generation who saw such mighty displays of God’s power became a symbol of faithlessness (Neh. 9:15-17, Ps. 106:24-26, 1 Cor. 10:5-10).

 God promises His children gifts that are beyond human reach. That is why they are based on grace and are accessible only through faith. Hebrews 4:2 explains that the promise Israel received “was of no value to them, because they did not share the faith of those who obeyed” (Heb. 4:2, NIV).

 Israel traveled to the borders of the Promised Land as a people. When the people were faced with contradictory reports, they identified with those who lacked faith. Faith, or lack of it, is contagious. That is why Hebrews admonishes its readers to “exhort one another” (Heb. 3:13), “to stir up one another to love and good works” (Heb. 10:24, ESV), and to “[s]ee to it that no one fails to obtain the grace of God” (Heb. 12:15, ESV).