The Indicative/Imperative Relationship and the Old Testament's If/Then Statements: An Impasse? -- Part 1

I am in the middle of a 9 week overview series on the book of Deuteronomy. The significant structure, declarative nature, and theological depth of the book make it a favorite to study and a real joy to teach. But it also provides a few challenges to the Christian reader. The conditional 'if/then' statements are one such challenge. In their positive form, they basically follow this pattern: 'If you obey, then you will receive....'

The indicative/imperative relationship provides a useful paradigm for understanding God's relationship to his people and for his people's relationship to Himself.

In the NT, this relationship is often explicit in the text and always implicit in the literary and/or theological context. In Paul, the relationship can be seen within the structure of whole epistles (Romans [1-11/12-16] and Ephesians [1-3/4-6]) and within countless single sentences. Of the latter, Galatians 5:1 is a clear example.
--Indicative: "For freedom Christ has set us free;"
--Imperative: "stand firm therefore, and do not submit again to a yoke of slavery."

Oftentimes the NT authors use 'therefore' to clearly mark the imperative as a subordinate inference of the indicative. Whether or not such a marker is present, the relationship is always "indicative; therefore, imperative." It is never "imperative; therefore, indicative." Theologically, the relationship is always "You are accepted by God in Christ; therefore, obey" and never "You obey; therefore, you are accepted by God."

But what about the OT? Does this indicative/imperative relationship require the Christian gospel for its indicative truths? Is it thus necessarily unique to the NT? Or do the OT authors use other indicative truths to ground their imperatives? If so, are the indicative truths always implicitly redemptive? That is, does the OT always follow this same indicative/imperative relationship implicitly, if not explicitly?

To put it frankly, how does one handle the common 'if/then' sentences, especially in the Torah? Aren't these conditional sentences antithetical to the indicative/imperative relationship patterned in the NT?

To answer these question, I'd like to use Deuteronomy as my test case. In posts to follow, focus will be given to the general stipulations of chapters 5-11 and to the conditional (if/then) formulas repeated throughout Deuteronomy.