The body is a slave, the soul a sovereign, and therefore it is due to Divine mercy when the body is worn out by illness: for thereby the passions are weakened, and a man comes to himself; indeed, bodily illness itself is sometimes caused by the passions.

The true aim of our Christian life consists in the acquisition of the Holy Spirit of God. As for fasts, and vigils, and prayer, and almsgiving, and every good deed done for Christ's sake, they are only means of acquiring the Holy Spirit of God.

Prayer, fasting, vigils, and all other Christian practices, however good they may be in themselves, certainly do not constitute the aim of our Christian life: they are but the indispensable means of attaining that aim. For the true aim of the Christian life is the acquisition of the Holy Spirit of God. As for fasts, vigils, prayer and almsgiving, and other good works done in the name of Christ, they are only the means of acquiring the Holy Spirit of God. Note well that it is only good works done in the name of Christ that bring us the fruits of the Spirit.

... only the good deed done for Christ's sake brings us the fruits of the Holy Spirit. All that is not done for Christ's sake, even though it be good, brings neither reward in the future life nor the grace of God in this life. That is why our Lord Jesus Christ said: 'He who gathers not with Me scatters' (Lk. 11:23).

...it is up to us to add labors to labors in order to go from strength to strength (Ps. 83:7), and to come to the measure of the stature of the fullness of Christ (Eph. 4:13)?

The body is a slave, the soul a sovereign, and therefore it is due to Divine mercy when the body is worn out by illness: for thereby the passions are weakened, and a man comes to himself; indeed, bodily illness itself is sometimes caused by the passions.

The human spirit lies open to God alone, for it is a fathomless depth.