How many winds of doctrine have we known in recent decades, how many ideological currents, how many ways of thinking. The small boat of the thought of many Christians has often been tossed about by these waves - flung from one extreme to another: from Marxism to liberalism, even to libertinism; from collectivism to radical individualism; from atheism to a vague religious mysticism; from agnosticism to syncretism and so forth. Every day new sects spring up, and what St Paul says about human deception and the trickery that strives to entice people into error (cf. Eph 4: 14) comes true.
Today, having a clear faith based on the Creed of the Church is often labeled as fundamentalism. Whereas relativism, that is, letting oneself be "tossed here and there, carried about by every wind of doctrine", seems the only attitude that can cope with modern times. We are building a dictatorship of relativism that does not recognize anything as definitive and whose ultimate goal consists solely of one's own ego and desires.
We, however, have a different goal: the Son of God, the true man. He is the measure of true humanism. An "adult" faith is not a faith that follows the trends of fashion and the latest novelty; a mature adult faith is deeply rooted in friendship with Christ. It is this friendship that opens us up to all that is good and gives us a criterion by which to distinguish the true from the false, and deceit from truth.
We must develop this adult faith; we must guide the flock of Christ to this faith. And it is this faith - only faith - that creates unity and is fulfilled in love.
(now Pope Benedict XVI)