What makes the resurrection important?

There's a trend in evangelical apologetics that's been evolving ever since John Warwick Montgomery. Montgomery stressed historical apologetics and the Resurrection. There are several reasons for this:

i) There's the intrinsic importance of the Resurrection.

ii) Apologists of this stripe consider the Resurrection to be the best-attested Biblical miracle. 

iii) Apropos (ii), they think they can make a good case for the Resurrection without presupposing the inspiration of the Bible. Even if you just treat the NT as "basically reliable" historical documents, that will get you the Resurrection. And once you've got the Resurrection, you can use that to retroactively validate other Biblical claims (so goes the argument).

Now, we can debate the merits of this approach as an apologetic strategy. Although I think this approach is deceptively simple, I don't think questions of apologetic strategy are all-important. There are different ways to defend the Christian faith, and it's useful to have more than one tool in our toolbox. 

The problem is when what started out as a particular apologetic strategy ends up defining the Christian faith. Prioritizing Christian doctrine.

Let's take a step back and ask, why is the Resurrection so important? Although Christians who've been conditioned by this apologetic strategy might be shocked to hear me say this, from a theological standpoint, the resurrection of Christ is less fundamental than the death of Christ.

No doubt the Resurrection is a fundamental tenet of the Christian faith. But the significance of the Resurrection is contingent on a prior event. if the Resurrection were an isolated event in the life of Christ, it would lose its larger significance.

The resurrection of Christ is important to Christians because Christian immortality is grounded in the immortality of Christ. The resurrection of Christ anticipates the resurrection of the just. Because he rose from the dead, we will rise from the dead–to enjoy eternal happiness.

But here's the catch. The resurrection of Christ, all by itself, is not a sufficient condition to cement that linkage. A necessary precondition is the remission of sin. Unless Christians (as well as OT saints) were forgiven and justified, they'd face eternal judgement rather than eternal bliss.

For Christians (and OT saints), the resurrection of Christ would be otiose apart from the death of Christ. Unless Christ died to redeem your sins, the resurrection of Christ would not entail the resurrection of the just. 

Absent penal substitution, Christians couldn't benefit from the resurrection of Christ. Absent vicarious atonement, there'd be no carryover from the resurrection of Christ to the resurrection of the just.

iv) Some apologists are oblivious to this connection because they approach the issue as historians rather than theologians. Their narrow historical methodology leads to a compartmentalized view of the Resurrection, as if the significance of the Resurrection is separable from penal substitution. But the theological significance of Easter Sunday is contingent on the theological significance of Good Friday. In that respect, the Crucifixion is more fundamental than the Resurrection. Unless Jesus atoned for your sin, you have no share in his Resurrection.