He tells him and all the apostles with solemn emphasis that there is no one that has left home or wife or brothers or parents or children for the sake of the kingdom of God who would not receive in return, as a reward of grace, much more, a hundred times more, even in this present world. Even here on earth, in Christ and in the Kingdom of Grace, a Christian finds full compensation for everything that he has given up and sacrificed in this world’s goods; for the standards of the kingdom of God are entirely different from those of the world, Mark 10, 30. And finally, when the time set by God has come, He will give to the believers the inheritance of eternal life, not on account of any works or sacrifice, but as a reward of grace. Then all that he may have been obliged to suffer, to sacrifice, to deny, will sink into insignificance and be forgotten in the enjoyment of the heavenly bliss.
—Paul E. Kretzmann, on Luke 18:28-30