Matthew 19:29

Not only the 12 Apostles but every self-sacrificing disciple will receive a reward for his or her sacrifice. Jesus meant that everyone who makes a sacrifice to follow Him will receive much more than he or she sacrificed as a reward. He did not mean that if one sacrifices one house he or she will receive 100 houses, much less 100 mothers or 100 fathers, etc. If a disciple leaves a parent to follow Jesus, he or she will find many more people who will be as a parent to him or her in the kingdom. God is no man’s debtor. Additionally that person will inherit eternal life. That is, he or she will enter into the enjoyment of his or her eternal life in the kingdom as heirs for whom their heavenly Father has prepared many blessings.

"We must remember that eternal life in the Bible is not a static entity, a mere gift of regeneration that does not continue to grow and blossom. No, it is a dynamic relationship with Christ Himself [cf. John 10:10; John 17:3]." [Note: Dillow, p. 136.]

Other passages that present eternal life as something the believer must work to obtain are Matthew 19:16; Mark 10:17; Mark 10:30; Luke 10:25; Luke 18:18; Luke 18:30; John 12:25-26; Romans 2:7; Romans 6:22; and Galatians 6:8. Eternal life is quantitative as well as qualitative.