The labels Summer and Winter Christian originated with Martin Marty's book A Cry of Absence: Reflections for the Winter of the Heart. Many years ago my ACU colleague Darryl Tippins introduced me to Marty's distinctions between a "winter" and "summer" spirituality. In my research I've spent a lot time trying to precisely unpack the distinctions between and the dynamics that characterize these two spiritualities.
Much of that work is summarized in Chapter 6 of my book The Authenticity of Faith, a chapter entitled "Sick Souls, Winter Christians and Saints of Darkness."
The heart of my analysis regarding Summer and Winter Christians begins by comparing what I call the polar versus circumplex models of faith and complaint.
Many Christian communities and believers implicitly or explicitly work with a bipolar model when it comes to relating complaint to faith. Complaint toward God involves experiences of lament, protest, disappointment, frustration, anger, and doubt toward/about God. According to the polar model these experiences and expressions of complaint are symptomatic of faith problems, and are thus the polar opposite of faith. According to this model, then, strong faith should be characterized by a lack of complaint. No lament. No protest. No doubt.
In short, the polar model suggests that faith and complaint are antithetical impulses.
In contrast to the polar model, a great deal of theological and psychological literature (which I describe in The Authenticity of Faith) suggests that the relationship between communion/engagement with God and compliant may be circumplex, not as polar opposites but as two dimensions existing at right angles.
This model suggests that communion/engagement with God and complaint can co-exist.
Faith, in short, can be a complex mixture of communion and compliant with God.
Now, if you read the bible (e.g., the Psalms) this observation should be obvious, but many Christians struggle with this idea because they are tacitly working with the polar model of faith. Which is why setting the two models visually side by side can be helpful and therapeutic for many Christians. They can begin to see what is going on:
Again, many churches and Christians are explicitly or implicitly working with the polar model of faith, viewing any complaint toward God as a failure of faith, as a faith problem.
The value of the circumplex model is that it allows us to view complaint as a legitimate expression of faith, as an experience that co-exists with faith, what might called the "winter experience of faith."
With the circumplex model in hand the Summer versus Winter experiences of faith can be contrasted as two different quadrants in the model:
As you can see in the top two quadrants, the distinction between Summer and Winter Christians is not a distinction between those who possess versus those who lack faith. Rather, the distinction between the Summer and Winter Christian is the degree to which complaint, lament or doubt intermingles with faith, communion and engagement with God.
Finally, we can think of these quadrants as being either episodic experiences or as spiritual temperaments. When I speak of "Summer Christians" or "Winter Christians" I'm speaking about spiritual temperaments or dispositions, people who tend to spend most if not all of their spiritual lives in a particular sector of the circumplex.
But these sectors can map episodic experiences as well. For example, a Summer Christian going through a season of lament or doubt could be described as "Summer Christian" who is going through a "winter Christian experience."