In the old covenant, God made us His people. Our responsibility in the covenant was "to walk in His ways and observe His statutes, commandments and decrees" (Dt 26:17). We were utterly incapable of the complete obedience called for in this covenant. So we broke the covenant.
Then God made a new covenant not just with the Jewish people but with all people. He covenanted not only to be our God but also our Father. We are not only His people but also His children. In this best and final covenant with God, our Father requires us not only to be obedient but even perfect (Mt 5:48). As children of God, we must act like God — even to the point of loving our enemies (see Mt 5:44). How could humanity, which failed in a lesser covenant, be perfect as our heavenly Father is perfect?
God the Father sent His Son Jesus to bring about the new covenant through Jesus' life, death, and resurrection. We must believe in Jesus and be baptized into Him (see Rm 6:3). In this way, we receive a new nature. In this nature, we have the grace to become perfect. We do this by following the Holy Spirit in Whom we are also baptized. In the baptized life of the new covenant, the life in the Spirit, we live in the new dimension of grace, holiness, perfection, light, freedom, power, and miracles.
In this Lent, as the catechumens of the world prepare to be baptized, let us sacrificially and joyfully prepare to renew our baptismal covenant at Easter.