Homily of H. H. Benedict XVI on the occasion of the closing of the Pauline Year

The words "adult faith" in recent decades have formed a widespread slogan. It is often meant in the sense of the attitude of those who no longer listen to the Church and her Pastors but autonomously choose what they want to believe and not to believe hence a do-it-yourself faith. And it is presented as a "courageous" form of self-expression against the Magisterium of the Church. In fact, however, no courage is needed for this because one may always be certain of public applause. Rather, courage is needed to adhere to the Church's faith, even if this contradicts the "logic" of the contemporary world. This is the non-conformism of faith which Paul calls an "adult faith". It is the faith that he desires. On the other hand, he describes chasing the winds and trends of the time as infantile. 

Thus, being committed to the inviolability of human life from its first instant, thereby radically opposing the principle of violence also precisely in the defence of the most defenceless human creatures is part of an adult faith. It is part of an adult faith to recognize marriage between a man and a woman for the whole of life as the Creator's ordering, newly re-established by Christ. Adult faith does not let itself be carried about here and there by any trend. It opposes the winds of fashion. It knows that these winds are not the breath of the Holy Spirit; it knows that the Spirit of God is expressed and manifested in communion with Jesus Christ. 

However, here too Paul does not stop at saying "no", but rather leads us to the great "yes". He describes the mature, truly adult faith positively with the words: "speaking the truth in love" (cf. Eph 4: 15). The new way of thinking, given to us by faith, is first and foremost a turning towards the truth. The power of evil is falsehood. The power of faith, the power of God, is the truth. The truth about the world and about ourselves becomes visible when we look to God. And God makes himself visible to us in the Face of Jesus Christ. In looking at Christ, we recognize something else: truth and love are inseparable. In God both are inseparably one; it is precisely this that is the essence of God. For Christians, therefore, truth and love go together. Love is the test of truth. We should always measure ourselves anew against this criterion, so that truth may become love and love may make us truthful.

Letter to the Phillipians 1, 2-11

grace to you and peace from God our Father and the Lord Jesus Christ.  I give thanks to my God at every remembrance of you,  praying always with joy in my every prayer for all of you,  because of your partnership for the gospel from the first day until now.  I am confident of this, that the one who began a good work in you will continue to complete it until the day of Christ Jesus.  It is right that I should think this way about all of you, because I hold you in my heart, you who are all partners with me in grace, both in my imprisonment and in the defense and confirmation of the gospel.  For God is my witness, how I long for all of you with the affection of Christ Jesus.  And this is my prayer: that your love may increase ever more and more in knowledge and every kind of perception,  to discern what is of value, so that you may be pure and blameless for the day of Christ,  filled with the fruit of righteousness that comes through Jesus Christ for the glory and praise of God.