Having reminded the leaders of Israel that God’s people have sinful natures and that pagan religions do not lead to God, Joshua also encourages them with God’s promises.

Positively, he testifies that the Lord always does what he says in terms of coming to help Israel. So in Joshua 23:3–4 God promised to drive out the nations and he has done exactly that. In Joshua 23:5 and Joshua 23:10, the Lord has promised he will help you to fight the remaining Canaanites, so trust him to come to your aid. By his Spirit, God will help you to put to death your sinful nature (Romans 8:13). He will empower you to establish new habits that are healthy and good, so that you can cling to him and have your mind renewed by his Word (Romans 12:1–2).

But it is not only God’s promises of help that we must remember. Joshua also draws attention to promises of wrath—promises of judgment to come for those who ignore God and reject his commandments; promises of curses and exile (Joshua 23:14–16).

As we read these promises today, we are right to recognize that they are the covenant curses which were peculiar to the time of the old covenant. Blessings for obedience, curses for disobedience—those were the promises made in Deuteronomy 28:1–68. Living in the new covenant, we are not in the land of Canaan, and thus these curses and warnings do not apply to us in the same way. What is more, Christ redeemed us from the curse of the law by becoming a curse for us. He suffered and died so that the blessing of Abraham might also come to us (Galatians 3:10–14).

Nevertheless, we should still heed the warning of God’s Word. Almost like we find in the book of Hebrews. There is certainty of salvation for those who trust in Christ but also a warning not to harden your heart (Hebrews 4:1–16). A warning not to rest in complacency and think that you will continue in the Christian faith without any effort on your part. A warning not to stay away from the gathering of God’s people (Hebrews 10:19–25), a warning not to allow public reproach and threat of fines to keep us from costly obedience (Hebrews 10:32–34). These warnings are given to us so that we will hear them and respond with action. They are warnings that cause God’s children to hold fast to Christ and cling to him. They are warnings which are meant to encourage obedience by reminding us that it is through his church that God wants to work out the salvation in us.