Clement: Faith is a grace

Faith is a grace which from what is indemonstrable conducts to what is universal and simple, what is neither with matter, nor matter, nor under matter.  (ἡ πίστις δὲ χάρις ἐξ ἀναποδείκτων εἰς τὸ καθόλου ἀναβιβάζουσα τὸ ἁπλοῦν, ὃ οὔτε σὺν ὕλῃ ἐστὶν οὔτε ὕλη οὔτε ὑπὸ ὕλης) (Str. 2.4.14.3-2.4.15.1)

"It was not without the wood of the tree that He came to our knowledge."

Moses says, “Show Thyself to me,”—intimating most clearly that God is not capable of being taught by man, or expressed in speech, but to be known only by His own power. For inquiry was obscure and dim; but the grace of knowledge is from Him by the Son. Most clearly Solomon shall testify to us, speaking thus: “The prudence of man is not in me: but God giveth me wisdom, and I know holy things.” Now Moses, describing allegorically the divine prudence, called it the tree of life planted in Paradise; which Paradise may be the world in which all things proceeding from creation grow. In it also the Word blossomed and bore fruit, being “made flesh,” and gave life to those “who had tasted of His graciousness”; since it was not without the wood of the tree that He came to our knowledge. For our life was hung on it, in order that we might believe. (ἐκρεμάσθη γὰρ ἡ ζωὴ ἡμῶν εἰς πίστιν ἡμῶν.)” (Clement, Str. V 71,5-V 72,4)

Basil on faith and knowledge

 “Generally, in the sciences, faith goes before knowledge, but in our own teaching, even if someone says that knowledge must exist before faith, we do not disagree - knowledge, however, commensurate with human comprehension.” (Basil, Ep. 235, 1, 12–14)

Origen on the faith about God being through His Son

"[...]our faith about God is through His Son, who confirms that faith in us. And Celsus cannot show that there is any discord in our belief about the Son of God. Indeed, we worship the Father by admiring His Son who is Logos, Wisdom, Truth, Righteousness, and all that we have learnt the Son of God to be - him, in fact, who was born of a Father of this nature." (Con. Cel. VIII,13)

"[...]faith, which the Greeks disparage, deeming it futile and barbarous, is a voluntary preconception, the assent of piety"

"[...]faith, which the Greeks disparage, deeming it futile and barbarous, is a voluntary preconception, the assent of piety—“the subject of things hoped for, the evidence of things not seen,” according to the divine apostle. “For hereby,” pre-eminently, “the elders obtained a good report. But without faith it is impossible to please God.” Others have defined faith to be a uniting assent to an unseen object, as certainly the proof of an unknown thing is an evident assent. If then it be choice, being desirous of something, the desire is in this instance intellectual. And since choice is the beginning of action, faith is discovered to be the beginning of action, being the foundation of rational choice in the case of any one who exhibits to himself the previous demonstration through faith. Voluntarily to follow what is useful, is the first principle of understanding. Unswerving choice, then, gives considerable momentum in the direction of knowledge. The exercise of faith directly becomes knowledge, reposing on a sure foundation. Knowledge, accordingly, is defined by the sons of the philosophers as a habit, which cannot be overthrown by reason. Is there any other true condition such as this, except piety, of which alone the Word is teacher? I think not. Theophrastus says that sensation is the root of faith. For from it the rudimentary principles extend to the reason that is in us, and the understanding. He who believeth then the divine Scriptures with sure judgment, receives in the voice of God, who bestowed the Scripture, a demonstration that cannot be impugned. Faith, then, is not established by demonstration. “Blessed therefore those who, not having seen, yet have believed.” The Siren’s songs, exhibiting a power above human, fascinated those that came near, conciliating them, almost against their will, to the reception of what was said." (Clement of Alexandria, Str. 2.2)