When a man receives something Divine, in his heart he rejoices; but when he receives something diabolic, he is disturbed. The Christian heart, when it has received something Divine, does not demand anything else in order to convince it that this is precisely from the Lord; but by that very effect it is convinced that this is heavenly, for it senses within itself spiritual fruits: love, joy, peace, and the rest (cf. Gal. 5:22).
Seraphim of SarovGod is a fire that warms and kindles the heart and inward parts. Hence, if we feel in our hearts the cold which comes from the devil - for the devil is cold - let us call on the Lord. He will come to warm our hearts with perfect love, not only for Him but also for our neighbor, and the cold of him who hates the good will flee before the heat of His countenance.
Seraphim of SarovIn spite of our sinfulness, in spite of the darkness surrounding our souls, the Grace of the Holy Spirit, conferred by baptism in the name of the Father and the Son and the Holy Spirit, still shines in our hearts with the inextinguishable light of Christ ... and when the sinner turns to the way of repentance the light smooths away every trace of the sins committed, clothing the former sinner in the garments of incorruption, spun of the Grace of the Holy Spirit. It is this acquisition of the Holy Spirit about which I have been speaking.
Seraphim of Sarov