For emphasis Jesus introduced His reply with the preface that affirmed the truthfulness of what followed. Everyone who denies himself or herself the normal comforts and contacts of life to advance God"s mission will receive a greater reward from God for doing so. Luke used the phrase "for the kingdom of God" ( Luke 18:29; cf. Luke 18:25) whereas Matthew used "for my sake" ( Matthew 19:29) and Mark wrote "for my sake and for the gospel"s sake" ( Mark 10:29). These are all synonymous concepts. [source][source][source]
First, that one will receive deeper spiritual comfort and more satisfying human contacts in the present life (cf. Acts 2:44-47; Acts 4:32-37). Second, he or she will receive an even better and enduring life in the coming kingdom. Jesus and the apostles spoke of eternal life as a reward for self-sacrifice ( Matthew 19:29; Mark 10:30; John 12:25-26; Romans 2:7; Romans 6:22; Galatians 6:8) and as the gift of God that comes to everyone who trusts in Jesus Christ ( Romans 6:23). [1] Jesus mentioned it here with rewards because it provides the ultimate contrast with what disciples give up now. Giving up a wife may refer to giving up marriage rather than leaving a wife, or periods of separation to engage in kingdom business may be in view. [source][source][source]