From the Preface of Exploring Judaism: A Reconstructionist Approach by Rebecca T. Alpert and Jacob J. Staub:

One does not become a Reconstructionist simply by joining a Reconstructionist synagogue or by paying dues to a national organization. Our name itself indicates active participation in a shared process. No mere passive adjective describing a “type” of Judaism, our name says that each of us engages in just that – the reconstruction of Jewish life and tradition to integrate it with the particular lifestyle that each of us chooses. The Reconstructionist community is not a body of synagogues and rabbis that others merely support. It is rather a community in the full sense of the term, in which no one’s duty may be done vicariously by others. It is a community of Jews who commit themselves to ongoing study, to discussion of issues, and to a life of intelligent decision making. . .

The term “reconstruct” involves two clear assumptions. First, that each generation prior to our own played a role in constructing the Judaism which is now ours. Thus, traditional meanings have changed over time; they have not always been conserved in the past and certainly should not be seen as permanent today. Reconstructionists use the foundation and building blocks they have inherited from the past, reordering and adding to them so that they fit the needs, values, and tastes of this generation, without altering them in ways that would make them unrecognizable or sap their richness.

Second, that the basic structures of Jewish life are in need of serious rethinking. These include such institutional structures as the Jewish community and the synagogue, with special reference to the quality of interpersonal relationships and value orientations that exist within them. Reconstruction also applies to the organized Jewish community as a whole, including the nature of diaspora Jewry’s all-important relationship to the State of Israel and the centers of Jewish creativity there. It applies to the basic intellectual structures of Jewish life as well as to the social ones – to the way we think about God, to traditional religious language, to prayer, and to the role of the Jewish people in history.

From Judaism as Civilization by Mordecai M. Kaplan:

The Jew’s religion is but one element in his life that is challenged by the present environment. It is a mistake, therefore, to conceive the task of conserving Jewish life as essentially a task of saving the Jew’s religion. When a person is about to abandon a house for fear that it might fall about his ears at any moment, it is folly to try to convince him that he ought to remain in it because of the beautiful frescoes on the walls. Jewish life is becoming uninhabitable because it is in danger of collapse. The problem is how to make it habitable. To drop the metaphor and return to the more abstract method of viewing the problem of Judaism, the task now before the Jew is to save the otherness of Jewish life; the element of unlikeness will take care of itself. . .

Judaism as otherness is . . .something far more comprehensive than Jewish religion. It includes that nexus of a history, literature, language, social organization, folk sanctions, standards of conduct, social and spiritual ideals, esthetic values, which is their totality forma civilization. . .

Judaism is but one of a number of unique national civilizations guiding humanity toward its spiritual destiny. It has functioned as a civilization throughout its career, and it is only in that capacity that it can function in the future. . .

The Neo-Orthodox Jew meets the challenge of the modern environment by a reaffirmation of his faith in tradition. He bases his veneration of the content of Judaism on the high authority of those from whom that content is derived. Their authority, in turn, it is assumed, is validated by the supernatural revelation of God’s will. The Reformist Jew rejoices to find in Judaism truths of universal application, the unity of God, the brotherhood of man, the supremacy of righteousness. But for the Jew who approaches Judaism as a civilization, the test for any form of adjustment will not be whether it conforms to the accepted teachings of revelation, not whether it is consistent with the universal aims of mankind. His criterion will be: does that adjustment proceed from the essential nature of Judaism? Is it inherently interesting? The thing that makes Judaism a vital reality for him is not a regimen of conduct or a system of thought. He realizes that the force of a social heritage lies not in its abstract and universal values, but in its individuality, in its being unalterably itself, and no other. This individuality he knows from within. It is an immediate and untransferable experience. It is as interesting to him as anything that is part of his own personality can be.

From Staub, Jacob, “How Can Reconstructionists Pray?” in Schein, Jeffrey, ed., Connecting Prayer and Spirituality

If you don’t believe in a “traditional” God, why do you bother attending services in synagogue? Why go to the trouble and expense of publishing a new prayerbook?

These kinds of questions are asked of Reconstructionists all the time. They are based on the assumption that “prayer” means “petitionary prayer” – prayer in which the one who prays asks God to grant a request or a wish. Prayer is thought of as a conversation with God. But Reconstructionists do not believe in a God who is supernatural – a God who intervenes in nature and causes things to happen in violation of the laws of nature. And Reconstructionists do not believe that God can be described anthropomorphically – as having human form and human characteristics, as if God were an invisible person in Heaven watching over us. So if I don’t believe that God literally hears my prayers, and if I don’t believe that God responds to my prayerful wishes, why do I bother to open a siddur?

. . . What [Reconstructionists] . . . share is a conviction that a) the words of the Torah . . . were not literally spoken and commanded by God at Sinai and b) that nevertheless our inherited tradition (including the prayerbook) is an invaluable treasure that can help us to unfold the deeper meaning of our lives and our relationship to God.

In other words, if I had brought a tape recorder to Mount Sinai, I believe there would have been no audible divine voice to record; only the human side of the conversation was recordable. But I also believe that God was at Sinai, encountered by Moses, so that even though the words of the Torah are Moses’ human interpretation of God’s will, they are inspired by that encounter and contain divine insight.

And so with every divine-human encounter up to the present day: what we hear and understand of God is necessarily conditioned by who we are, by where and when we live, by our culture’s values, by our individual propensities. . . [W]e Reconstructionists don’t believe that everything that preceding generations said about God and about what God wants is true. But we do believe in a God who is beyond all of the historically conditioned human portraits of God. And we seek to express our intuitions of God in ways that both correspond to the teachings we inherit and that are compelling in the cultural idiom of our own day.