What then is faith?
According to the inspired definition given in the New Testament, “faith is the personal foundation of things hoped for, certainty about things that cannot be seen” (Heb 11:1). Faith means trusting in the unseen as though it were seen, so much so that what is hoped and waited for becomes, as it were, already present. Even a measure of natural faith is woven into all human life, as St Theophilus of Antioch observes:
Do you not know that faith is the leading principle in all matters? For what husbandman can reap, unless he first trusts his seed to the earth? Or who can cross the sea, unless he first entrusts himself to the boat and the pilot? And what sick person can be healed, unless first he trusts himself to the care of the physician? … If, then, the husbandman trusts the earth, and the sailor the boat, and the sick the physician, will you not place confidence in God, even when you hold so many pledges at His hand? (St Theophilus of Antioch, To Autolycus, 1.8)
Christian faith is anchored in the certainty that God is almighty and loving (Luk 1:37; 1Jo 4:8; see Q087, Q386). It is therefore not blind or irrational, for “ever since the creation of the world his invisible nature, namely, God’s eternal power and deity, has been clearly perceived in the things that have been made” (Rom 1:19–20; see Q012).
The sin and carnality5 at work in us incline us to suppress this knowledge of God; but through grace, repentance, and faith we obtain in Christ Jesus “the result of your faith, the salvation of your souls” (1Pe 1:9; see Q001, Q484). St Cyril of Jerusalem distinguishes two dimensions of faith: the assent of the soul to the truths of the faith, and faith as a gift of grace bestowed by the Holy Spirit, which is able to move mountains (St Cyril of Jerusalem, Catechetical Lectures, 5.10–11; see Q003, Q008). Catechesis nourishes the first, and prays for the second.
Also “Concupiscence” (rendering Gk. ἐπιθυμία, “desire”; cf. the passions, πάθη), the disordered movement of desire in fallen humanity, the “concupiscence of the flesh” of 1Jo 2:16, which inclines the soul toward sin though it is not sin until the will assents. The Fathers treat it as a fruit of the ancestral fall and a chief object of ascetic labor (cf. St. Maximus the Confessor and St. Mark the Ascetic on the passions). It underlies carnality, the “mind of the flesh” opposed to the Spirit (Rom. 8:6–7).
