Selected quotes from St. Isaac the Syrian

"The soul keeps watch over the body, lest the crafty one take her captive through the enticements found in this age, and by troubled and erring thoughts. So long as the soul is closed behind the veil of the door of the flesh, she has no confidence, for there is no perfect freedom in this imperfect age. Every working of knowledge is for the sake of activity and training; the
working,  however, of faith is not performed in deeds, but is accomplished by spiritual insights through the naked activity of the soul, and it transcends the senses. For faith is more subtle than knowledge, just as knowledge is more subtle than palpable deeds."

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"Those who fear God, O beloved, are cheerfully assiduous in keeping the commandments, even if labours are required to do so and they imperil themselves for their sake. The Lifegiver confined the fullness of the commandments in, and made them to hang upon, two which embrace all: the love of God, and a love similar thereto, the love of His image."

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"Hold faith and humility fast within you; for through them you will find mercy, help, and words spoken by God in the heart, along with a protector who stands beside you both secretly and manifestly. Do you wish to obtain these things, which are a fountain of life? From the very onset take hold of simplicity. Walk before God in simplicity and not with knowledge. Simplicity is attended by faith; but subtle and intricate deliberations, by conceit; and conceit is attended by separation from God."