"Rejoice ye in that day, and leap for joy: for, behold, your reward is great in heaven: for in the like manner did their fathers unto the prophets" (Luke 6:23).
Sometimes great rewards are promised to those who help locate dangerous criminals, or to those who win a lottery, but such pecuniary rewards are trivial compared to those awaiting all the faithful servants of Christ. The "great reward" promised by Christ in our text is specifically for those believers who willingly have endured hatred and ostracism, reproach, and slander "for the Son of man's sake" (v.22).
Such rewards are distinct from salvation, of course, for that reward is given only "to him that worketh not, but believeth on Him that justifieth the ungodly" (Romans 4:5). "Not by works of righteousness which we have done, but according to His mercy He saved us, by the washing of regeneration, and renewing of the Holy Ghost; Which He shed on us abundantly through Jesus Christ our Savior" (Titus 3:5-6).
That is, salvation is a free gift, received only through personal faith in Christ and His sacrificial death for our sins. Rewards, on the other hand, are earned by faithful witness and work for Christ. In that day when "we must all appear before the judgment seat of Christ" (II Corinthians 5:10), many will learn to their dismay that, although they have indeed received everlasting life, they will have very little reward. For "the fire shall try every man's work of what sort it is" (I Corinthians 3:13)--not the quantity, but its quality and fidelity to God's Word. Then, "If any man's work shall be burned, he shall suffer loss: but he himself shall be saved" (v.15).
We need to remember that one of the last and thus most significant promises of Christ was: "Behold, I come quickly; and my reward is with me, to give every man according as his work shall be" (Revelation 22:12). HMM