An act of faith requires the use of the understanding and the use of the will.  The mysteries surpass our natural understanding; they are, furthermore, to be believed in a supernatural manner, and we require, therefore, the supernatural light of faith, added to the natural light of our understanding, and we require also that our natural willpower be strengthened by the supernatural power of grace.  This light and this power we receive in Baptism.  The supernatural light of faith qualifies us to understand that the truths revealed by God are divine.

In order to believe it does not suffice to know the divine truths as the Church teaches them, we must also, of our own free will, assent to them, and acknowledge as divine truths even those mysteries which surpass our human understanding.  To that extent faith is a matter of the will.  God, through the light and the power of the grace of faith, comes to the assistance of our reason and will, in order that we may confidently submit both to divine revelation, that is, to God.  In order that the infused virtue of faith may be meritorious for us, we must co-operate with grace by readily submitting our understanding and our will to divine revelation.  Then this virtue of faith will not only be an infused one but, also, will be an acquired one and thus become a meritorious virtue.  This actual and acquired virtue is for every adult the first condition of salvation.  Still the acceptance of the divine doctrine is alone not sufficient for salvation.  We must live in accordance with our faith; we must do good and shun evil.  Such is the teaching of faith.  “He truly believes who practises what believes,” says St. Gregory, and St. James tells us that “Faith without works is a dead faith and avails nothing to salvation.”  A living faith is the first condition and the beginning of salvation.  Eternal happiness consists, as we are aware, in the vision of God.  The living faith is a beginning of this vision.  We know God through the Christian faith, but only as in a mirror.  “Now I know in part:  but then I shall know even as I am known” (I.  Cor. xiii, 12).

II.  The second of the divine virtues is hope.  Christian hope is a virtue infused into our souls by which we confidently expect of God everything which He has promised us through the merits of Christ.  God has promised us eternal happiness, also all things which we stand in need of, and that are profitable for us in our endeavor to attain eternal happiness.  Jesus has merited these for us, and God has promised them to us for the sake of the merits of Jesus Christ.  And because God has promised them to us we must confidently expect and hope for them, because God is omnipotent, merciful and faithful to His promises.

This Christian confidence in God is bestowed by the virtue of hope, infused into our souls at Baptism.  We must frequently exercise it in order to make it conducive to salvation.