When one studies the Pentateuch (i.e., the first five books of the Old Testament), it is easily seen that the Hebrew people had a special relationship with God. They had a covenant relationship with Him. It was an intimate bond that involved special expectations, privileges, and blessings. God's love made this relationship possible at Sinai--the Hebrew people did not earn it. They were physically born into it, and the males were circumcised as a sign of that covenant (cf. Gen. 17:11).
There was a perpetual need for the Israelites to renew their covenant with God on a personal, meaningful level and Moses encouraged them to do this. He extensively reviewed the covenant with them approximately forty years after it was established (cf. Deut. 5:1-3). Moses didn't want the new generation to repeat the mistakes of their parents. He wanted them to understand that God requires more than good intentions or lip service.
Moses obviously did a good job developing the covenant relationship between God and the Israelites. The people, for the most part, faithfully served the Lord long after Moses died (cf. Jud. 2:7ff). Tragically though, as time went on, the nation did not continue to remember or honor the special relationship they had with God. Instead of continuing to serve Him, they followed their own path of perversion and idolatry. Consequently, God withheld blessings that He longed to pour out upon them. He cursed them for their wicked ways and eventually allowed their sins to sweep them into captivity.
Even today, God has a covenant relationship with a special people. This bond (which also cannot be earned) is based on the new covenant that was made possible by God's love at the cross of Calvary. Today, as in Moses' day, the people who obey His voice and keep His covenant are a special treasure to Him above all others. However, in stark contrast to the old covenant, God's people today are not recognized by their physical ancestry, and they are not physically born into a covenant relationship. Rather, they are spiritually born into it (cf. Gal. 3:26-29)!
One beautiful aspect of the new covenant is that it is open to all who obey the gospel and are born again (i.e., converted). When one obeys the gospel by believing in Jesus Christ, turning from sin, and being immersed in water for the forgiveness of his transgressions, he enters into a bond with the Lord that involves special expectations, privileges, and blessings (cf. Eph. 1:3). God demands that His children today--that is, Christians--continually cultivate and renew their covenant bond with Him. As with the Israelites of old, He wants us to remember the great things He has done for us. He wants us to learn from the past. He wants us to understand that He expects more than a verbal confession of faith and submission to the act of baptism. He wants us to deliver more than good intentions. He wants us to be faithful to the covenant we make with Him when we obey the gospel. He wants us to keep Him first in our lives!
If the Israelites had remained true to their covenant bond with God, they would have never fallen into captivity. They would have reaped blessing upon blessing. Friends, if you are a Christian, be mindful of the covenant you have entered into with the Lord. If you stay true to it, you will never fall into apostasy (cf. II Pet. 1:10). Begin each day by purposing to honor that covenant to the best of your ability. Dear listener, if you are not a Christian, I urge you to obey the gospel today!