Here is collection of posts by Jason Engwer along with links to issues in Isaiah 9:

The first seven verses of Isaiah 9 are highly significant, but usually underestimated, in a lot of important contexts. They have implications for Jesus’ identity, how he viewed himself, who he claimed to be, how he was perceived early on, the continuity between the gospels’ accounts of his childhood and their accounts of his adulthood, some prophecy fulfillments that are highly evidential, and other significant issues. I’ve written many posts on Isaiah 9 over the years, and I want to produce a collection of links to some of those posts, so that they can be accessed more easily in one place. I expect to update this post periodically when warranted.

Here’s a post on the evidence for the deity of the figure referred to in Isaiah 9. Another post addressed the evidence against seeing Hezekiah as the fulfillment of the passage.

I’ve interacted with some critics of a traditional Christian interpretation, such as Tovia Singer and some other posters on his YouTube channel, as discussed here. The YouTube thread addresses the tenses in Isaiah 9, whether Hezekiah fulfilled the passage, and some other issues. And here’s a response I wrote to Pete Enns. I also wrote a review of a debate between two Christians and two Muslims (Shabir Ally and Yusuf Ismail) on Isaiah 9:6.

The post here provides an overview of the evidence that Jesus viewed himself as the figure of Isaiah 9 and the implications of that fact. I’ve written at length about the evidence for Jesus’ identifying himself as that figure of Isaiah 9 in John 8:12, too much for me to link here. But this post is a good representative example. Another post discusses some themes found later in John 8 that provide further evidence of an Isaiah 9 backdrop. This post summarizes the evidence for Jesus’ relationship with Galilee and the regions of Zebulun (Nazareth) and Naphtali (Capernaum) in particular. Here’s a post discussing the evidence for Jesus’ being in Nazareth from an early age and the significance of his being there so early. Another post discusses some other evidence for Jesus’ residence in Nazareth. This post discusses some of the evidence for Jesus’ residence in Capernaum and the significance of his time there.

Isaiah 9 is also relevant in the context of Easter. See here for an overview.

The post here explains how Jesus’ fulfillment of Isaiah 9:1 can be used as part of a larger geographical argument for prophecy fulfillment.

Elsewhere, I discussed the advantages of arguing for Jesus’ self-perception and identity on the basis of Isaiah 9.

Triablogue: Isaiah 9 Resources