I thought this insight from a paper by Sandra Schneiders was helpful:

Paul Lakeland, in his very enlightening work on postmodernism, makes an important suggestion about how a Christian believer might reconcile the total claim of her or his faith with the openness to other faiths that is necessary for movement toward unity through honest dialogue. He says that we must enter the arena of dialogue with our own faith tradition behind rather than in front of us. In other words, we do not advance as onto a field of battle with our tradition as shield against heresy or paganism or, worse yet, as a sword with which to vanquish the other. Nor, however, do we check our faith tradition at the door of the conference room and enter as a religious ‘tabula rasa’. Rather, we enter undefended, securely rooted in our Christian faith tradition that we have internalised through study and practice as our own living spirituality, knowing that our truth can never be ultimately threatened by the truths of the other. What will surely be threatened and must eventually be surrendered are the nonessentials we have absolutized. Beyond that, much that we had never encountered or that we had ruled out ‘a priori’ because we thought we understood it will probably be added to our picture of reality.

 M. Schneiders, IHM. Religion and Spirituality: Strangers, Rivals or Partners, The Santa Clara Lectures (California), Vol. 6, No.2, February 2000, pp1-26
Paul Lakeland, Postmodernity: Christian Identity in a Fragmented Age (Minneapolis: Fortress, 1997)