From: Mark 10:28-31
Poverty and Renunciation (Continuation)
 Peter began to say to Him (Jesus), "Lo, we have left everything and followed You."  Jesus said, "Truly, I say to you, there is no one who has left house or brothers or sisters or mother or father or children or lands, for My sake and for the Gospel,  who will not receive a hundredfold now in this time, houses and brothers and sisters and mothers and children and lands, with persecutions, and in the age to come eternal life.  But many that are first will be last, and the last first."
28-30. Jesus Christ requires every Christian to practise the virtue of poverty: He also requires us to practise real and effective austerity in the possession and use of material things. But of those who have received a specific call to apostolate--as in the case, here, of the Twelve--He requires absolute detachment from property, time, family, etc. so that they can be fully available, imitating Jesus Himself who, despite being Lord of the universe, became so poor that He had nowhere to lay His head (cf. Matthew 8:20). Giving up all these things for the sake of the Kingdom of Heaven also relieves us of the burden they involve: like a soldier shedding some encumbrance before going into action, to be able to move with more agility. This gives one a certain lordship over all things: no longer the slave of things, one experiences that feeling St. Paul referred to: "As having nothing, and yet possessing everything" (2 Corinthians 6:10). A Christian who sheds his selfishness in this way has acquired charity and, having charity, he has everything: "All are yours; you are Christ's; and Christ is God's" (1 Corinthians 3:22-23).
The reward for investing completely in Christ will be fully obtained in eternal life: but we will also get it in this life. Jesus says that anyone who generously leaves behind his possessions will be rewarded a hundred times over in this life.
He adds "with persecutions" (v. 30) because opposition is part of the reward for giving things up out of love for Jesus Christ: a Christian's glory lies in becoming like the Son of God, sharing in His cross so as later to share in His glory: "provided we suffer with Him in order that we may also be glorified with Him (Romans 8:17); "all who desire to live a godly life in Christ Jesus will be persecuted' (2 Timothy 3:12).
29. These words of our Lord particularly apply to those who by divine vocation embrace celibacy, giving up their right to form a family on earth. By saying "for My sake and for the Gospel" Jesus indicates that His example and the demands of His teaching give full meaning to this way of life: "This, then, is the mystery of the newness of Christ, of all that He is and stands for; it is the sum of the highest ideals of the Gospel and of the Kingdom; it is a particular manifestation of grace, which springs from the paschal mystery of the Savior and renders the choice of celibacy desirable and worthwhile on the part of those called by our Lord Jesus. Thus, they intend not only to participate in Christ's priestly office, but also to share with Him His very condition of living" (Paul VI, "Sacerdotalis Coelibatus", 23).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.