If there is a single question that underlies what we might term the "liberal" tendency within the Church, it would be "Is the Gospel being heard?" ... If there is a single question that underlies what we might term the "conservative" tendency within the Church, it would be "Is the Gospel being heard?"
As he illustrates with examples from Apostolic and Patristic times, these are two tendencies that have always existed in the Church. He goes on to suggest that individuals with one tendency ought to check their positions against the other:
Those whose instincts lead them to intone "Fidelity! Fidelity! Fidelty!" need to ask Paul's question about whether certain beliefs and practices are as inextricably linked to the Gospel as they believe. Those sympathetic to the "Pauline" question might do well to ask whether they are presenting the fullness of Christ or a pallid imitation that merely reflects culture rather than challenging it.
Let me just add that those with one tendency ought also to check their positions against their own tendency. Concern that the Gospel be heard can devolve into concern that the position statement be approved by consensus. Concern that the Gospel be heard can devolve into concern that the latest interview of a favored bishop be heard.
Oh, and this: Even if a particular temperament is properly associated with a particular group of people -- as above, or as in Chesterton's "progressives want to make new mistakes, conservatives want to keep making old ones" -- that doesn't mean everyone associated with the group has that temperament. "Non serviam" temperaments, for example, can make a home just about anywhere.