What God will we serve? And what long-held beliefs will we need to reconsider, Harris asks, as we seek to live out the call of Christ?
It's a long way in the biblical narrative from Joshua to Simon Peter.
Yet, it was only a week between sermons on these men nearly 60 years ago as churches in the Atlanta area were facing the challenges of the escalating resistance to court-ordered requirements to desegregate schools and other public services.
Our pastor was one of the 80 white Atlanta clergy who signed the famous Ministers' Manifesto of 1957 calling for communication, respect and reconciliation in the face of the rising tide of overt racism that was fueling the resistance.
Sometime not long after the manifesto was published, and amid considerable hostile reaction to it, he offered two sermons.
One cited the image of Joshua's calling on the people of Israel to "choose this day whom you will serve" (Joshua 24:14-15), and the second focused on the experience reported in Acts 10, as Simon is confronted with his own prejudice as he is called to visit the home of a Gentile.
As an adolescent in that context, the emphases of those sermons have had an indelible impact on my thinking.
The conclusion of the book of Joshua is set in a ceremony of covenant renewal. He reminds the people of the Lord's work on their behalf from Abraham's call through the Exodus and to the occupation of "land on which they did not toil, living in cities they did not build, and eating from vineyards and olive groves they did not plant."
In a context of the nostalgic appeal of the pre-covenant gods from their distant past, and the allure of the enticing gods of the sophisticated cultures among whom they now lived, Joshua draws a line in the theological sand, with his "Choose you this day whom you will serve ... but as for me and my house, we will serve the Lord."
When the journey of the covenant community is at this crucial point of challenge to its faithfulness, the choice is whether the guidance will come from the Lord of the Covenant or from the gods of culture, ancient or contemporary, whose guidance is packaged in established thought and values. This is not an isolated experience, it seems.
Simon Peter receives a vision while he is taking a nap before lunch, presumably hungry.
In the vision he is presented with all kind of animals, "clean and unclean" (by religious standards) and told to help himself to a feast.
He responds with admirable resistance that he has never violated the rules of what is clean and unclean, and he's not about to now.
Good boy, right? No, he receives what seems to be a rather stern reprimand that what God has made and offered to him, he has no business calling unclean.
This happens three times before he wakes and receives an invitation to visit the home of Cornelius, a Gentile, and to have fellowship with him.
It is easy to see the challenge to his thinking - even thinking sanctioned by his religious faith - that association with Gentiles is outside the realm of acceptability.
Acts presents this as a major obstacle for Simon Peter, but one he must clear on his journey of faithfulness, and significantly one that is there well after he has become one of the chief apostles.
These two episodes in the biblical narrative - Joshua's reminder that "this day" we choose whom we will serve, and the portrait of Simon as one who must continually live and work in the tension between what he has always been taught and what the call of Christ is beckoning him to become - offer a bifocal lens through which to see any number of "crises" that face communities of faith then and now.
Two sermons in a context of significant unrest and divisiveness, now 60 years later, still offer good guidance not only on racial issues but also on others, where the appeal of culture's gods and the power of long-held beliefs are obstacles to the call to community.
"Crisis" is a term that has come to mean an urgent and serious challenge to a person or group.
Originally a medical term referring to "the turning point of a disease," it has also come to mean a "critical" point at which a decision must be made to direct the future.
Issues become crises when a person's or group's response to them determines the course of personal or group history.
Pick a crisis - Joshua's challenge to the people of Israel, Jewish-Gentile relations in the first century, race relations in Atlanta 60 years ago or any of the issues that divide communities of faith today - the questions remain: What God will we serve? And what long-held beliefs will we need to reconsider as we seek to live out the call of Christ?
Colin Harris is professor emeritus of religious studies at Mercer University and a member of Smoke Rise Baptist Church in Stone Mountain, Georgia.