Yes. If you deny that Adam was a historical person it negatively impacts other Christian doctrines. An affirmation of the historicity of Adam positively and necessarily connects with a number of key Christian doctrines.
Today I worked my way through the recently-released counterpoints book, Four Views on the Historical Adam (Zondervan). (Yes, “work through” means I did not read every page.) My favorite part of the book was the final essay, written by Philip G. Ryken, entitled: “We Cannot Understand the World or Our Faith without a Real, Historical Adam” (pages 267-279). It was written by a scholar-pastor who was asked to lay out what he understands to be the theological (and thus pastoral) implications of acceptance or denial of Adam and Eve as historical persons.
In his own words: “For what doctrines does it make a difference to defend the Adam of history? While we do not have the scope here to lay out a complete case, we can at least begin to show the foundational role that Adam plays in understanding human identity, forming a Christian worldview, and telling the gospel story.” (page 270)
Here are the doctrines Ryken presents that are affected by an understanding that Adam was in fact a historical person. Ryken makes his case primarily by mining the moments in Scripture where Adam is invoked as part of an argument. Following are his main points. (For the “fleshing out” of these points—excuse the pun—you’ll have to consult the essay itself.)
- The historical Adam gives confidence that the Bible is the Word of God.
- The historical Adam explains humanity’s sinful nature.
- The historical Adam accounts for the presence of evil in the world.
- The historical Adam (with the historical Eve) clarifies the biblical position on sexual identity and family relationships.
- The historical Adam assures us that we are justified before God.
- The historical Adam advances the missionary work of the church.
- The historical Adam secures our hope in the resurrection of the body and the life everlasting.
Here is an excerpt from his conclusion:
“What should be unmistakable, however, is that defending or denying the historical Adam has a direct bearing on many areas of faith and practice. His person serves an integrating function in Christian theology. Far from being readily isolable from the rest of biblical doctrine or peripheral to a thoroughly Christian view of the world, Adam’s history and identity help us understand everything from creation to the consummation.” (page 278)
I recommend this essay to any Christian who cares about biblical theology but is also unsure about whether it makes any difference that Adam was in fact a historical person. Ryken argues convincingly that from the standpoint of doctrine—and thus pastoral ministry—it certainly does.
 Gregory A. Boyd, who unsurprisingly lobbies for a big-tent orthodoxy (“maximal flexibility”), argues the opposite point-of-view in his essay on pages 255-266 of the same volume. He opines that it does not matter for a person’s faith whether Adam was actually a historical person. Boyd’s argument is essentially an argument from experience—from his own experience and from his observed experiences of Christians whose faith has been shaken as a result of encountering this question. In other words, in Boyd’s view, people need acceptance in a church body even if they aren’t sure about Adam’s historical existence. In stark contrast, Ryken’s article is essentially a biblical argument rather than an argument from experience even though it has significant practical ramifications.