"You know with all your heart and soul that not one of all the good promises the LORD your God gave you has failed." (Joshua 23:14)
Joshua is old and well advanced in years. He summons all Israel, their elders, heads, judges, and officials, and gives his farewell address. He recounts what God has done: driven out great and powerful nations before them, given them their territory. He urges them to hold fast to the LORD and love him. Be very strong; be careful to obey all the law Moses gave; do not turn aside to the right or to the left; do not associate with the remaining nations or invoke their gods. The LORD has driven out great and powerful nations before you; no one has been able to withstand you to this day.
Then the double-edged promise: You know with all your heart and soul that not one of all the good promises the LORD your God gave you has failed. Every promise has been fulfilled; not one has failed. But just as all the good things the LORD your God has promised you have come to you, so he will bring on you all the evil things he has threatened, until the LORD your God has destroyed you from this good land he has given you. Faithful obedience inherits the blessings; idolatry forfeits the land. Joshua has no illusions about which choice Israel will eventually make. The Catechism identifies this prophetic realism as the mark of all covenant faithfulness: the promises are real and the warnings are equally real (CCC 1963).
Brothers and sisters, not one promise has failed. Hold that in one hand. And in the other: the warnings are equally reliable. The same faithfulness that fulfils the blessings will fulfil the warnings. This is not meant to produce fear but seriousness: love the LORD, hold fast, do not turn aside. The stakes are real.
Lord God, not one of your good promises has failed. Give us the same certainty about your warnings, and let the certainty produce the obedience that inherits the blessing. Through Christ our Lord. Amen.