The book of Deuteronomy includes the words that Moses spoke to and wrote down for the second generation. Moses reviewed the forty years in the wilderness with them as they came out of the wilderness and camped east of the Jordan before they entered the Promised Land to begin the conquest their parents failed to do forty years before. Many of these people had never seen Egypt, but had been born in the wilderness. If everyone twenty years or older at the time of the failed conquest forty years before had died as the Lord swore they would, then there is no one except Moses, Joshua and Caleb older than sixty years old in the camp. Those who had been 0-20 years old at the time of the rebellion would now be 40-60 years old. These would remember Egypt from their childhood or their teenage years, but everyone 40 and under would have been born after the Exodus somewhere in the wilderness. The nation of Israel had become a generation of great faith and vitality!

This wilderness generation had grown up under the leadership of Moses, eating manna, living in a camp with God’s presence and daily hearing Moses' teaching. The book of Deuteronomy begins with Moses defining for them the borders of the land as God described it forty years earlier. This is the land that had been promised to them. It was the land promised to Abraham, Isaac and Jacob. The Promised Land extends from the Negev in the south to the Euphrates in the north. (Map)

Tertullian said this
in 210 AD:

“If the resurrection of the flesh is denied, a prime article of the faith is shaken…He, therefore, will not be a Christian who will deny this doctrine. For it is confessed by Christians.”