“will receive a hundredfold.” Not everyone who is saved and receives everlasting life will receive the same reward on the Day of Judgment. Those people who have obeyed God’s commands, and done more for Christ, will receive more (see commentary on 2 Cor. 5:10, “good or worthless”).
“life in the age to come.” This is the everlasting life that begins with the new Messianic Age, the Millennial Kingdom. [See Appendix 2: “Life in the Age to Come”, for commentary on this phrase.]