v. 12 If you heed these ordinances, by diligently observing them, the LORD your God will maintain with you the covenant loyalty that he swore to your ancestors
"Covenant" is one of the most important words in the Bible. It denotes the kind of relationship we have with God. It is a covenant relationship. This means that both sides of the relationship make promises that come with responsibilities. The promise is of loyalty one to another, a loyalty that is practiced in a particular way of life.
We have what we call "the Baptismal Covenant' (Book of Common Prayer, pp. 304-305) which is composed of the Apostles' Creed (the basic outline of our faith) and five practical questions that outline what we promise to do to keep our side of the covenant.
Christians talk about Jesus establishing a "New Covenant." What is "new" about it? Personally, I believe that it erases the great "if" of the opening verse of today's reading from Deuteronomy. The nature of the covenant we have with God through Jesus Christ is that God promises relationship with us unconditionally. There is no "if you do this, then I will do this." Instead there are the beautiful words of our baptismal service, "You are sealed by the Holy Spirit and marked as Christ's own for ever."
Our Covenant with God is such that we can trust God's "covenant loyalty" absolutely. The promises we make are very real, however. Our Baptismal Covenant comes with real promises, marking real responsibilities. They are not, however, the ways we make God love us. They are our joyful response to that love.
For you reflection here are the promises in the question form in which they are found in the Prayer Book:
Will you continue in the apostles' teaching and fellowship, in the breaking of bread, and in the prayers?
Will you persevere in resisting evil, and, whenever you sin, repent and return to the Lord?
Will you proclaim by word and example the Good News of God in Christ?
Will you seek and serve Christ in all persons, loving your neighbor as yourself?
Will you strive for justice and peace among all people, and respect the dignity of every human being?