The heart of what I call “catholic ecclesiology” is the conviction that Christ is fully and completely bound to the church as a corporate, visible body.
One can discuss catholic ecclesiology in terms of space, and in terms of time.
In space catholic ecclesiology is the idea that what binds the church together in unity is more fundamental than ideological positions which fall outside the purview of the mind of the universal church. Ultimately what binds the church together in unity is performance of the liturgy, which is the deepest corporate participation in Christ, with brothers and sisters in community. Hence I might vehemently disagree with a sister on all sorts of issues (for example, issues having to do with human sexuality), but we are still bound together in Christ. Hence we experience the deepest possible level of unity.
The denial of this spatial catholicity is seen when subcatholic ideologies are allowed to rupture the unity of the church, such that people who disagree, especially bishops, the focal point of unity in the church, no longer participate together in the (eucharistic) liturgy.
In time catholic ecclesiology is the idea that, over the peaks and valleys of history, the church will emerge faithful and victorious. Is the church locked into a vicious cycle of faithfulness and unfaithfulness, a seemingly endless repetition of the fate of Old Covenant Israel? Catholic ecclesiology says “no,” and insists that history is on the side of the institutional church, that the gates of hell will not prevail against it, that the church is qualitatively more spirit-infused than (because it is a fulfillment of) Old Covenant Israel.
The denial of this temporal catholicity is seen when theologians imply, or when people think or assume, that the church’s unfaithfulness will perpetuate itself indefinitely, a move which locates cosmic salvation outside the church, with a Christ who is isolated and disembodied.
Both denials, that of spatial catholicity and that of temporal catholicity, sever Christ from the church. But catholic ecclesiology always holds them together. Christ is the sacrament of God, and the church is the sacrament of Christ.