St. Gregory of Nyssa
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The temptations are profitable to the person that calmly endures them. Even if we are bothered by a passion, we must not be disturbed. If a person is disturbed when he is bothered by a passion that is a sign of ignorance, pride, not knowing his own condition and of idleness.
Practical Teaching on the Christian Life.
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"...anyone who receives the flesh of our Lord Jesus Christ and drinks His precious blood, as He Himself says, comes to be one with Him, mixed and mingled with Him, as it were, through partaking of Him, so that He comes to be in Christ, as Christ in turn is in him... the smallest portion of the sacrament mingles our whole body with itself and fills it with its own energy."
St. Cyril of Alexandria
Cyril of Alexandria: The Early Church Fathers by Norman Russell, Commentary on John 6:56; Routledge pg. 118