But mark both their faith, and their obedience. For though they were in the midst of their work (and you know how greedy a thing fishing is), when they heard His command, they delayed not, ... but "they forsook all and followed," ... Because such is the obedience which Christ seeks of us, as that we delay not even a moment of time.
-St. John Chrysostom, Homily 14 on Matthew 4, 4th Century


Prayer, fasting, vigil and all other Christian practices, however good they may be in themselves, do not constitute the aim of our Christian life, although they serve as the indispensable means of reaching this end. The true aim of our Christian life consists in the acquisition of the Holy Spirit of God.
-St. Seraphim of Sarov, The Acquisition of the Holy Spirit: Chapter 3, The Little Russian Philokalia Vol. 1; Saint Herman of Alaska Brotherhood pg. 79, 19th century