“Blessed are those who mourn, because they will be comforted.” This truth was revealed in the Old Testament in verses such as Isaiah 61:3, and it is not primarily referring to people being comforted in this life. As this verse promises, no matter how sad and difficult a person’s life is here on earth, and even if they die without experiencing true comfort, the promise will be fulfilled and they will be comforted in the next life.
[For more on the Beatitudes being about the future, see commentary on Matt. 5:3. For more on Christ’s coming kingdom on earth, see Appendix 3, “Christ’s Future Kingdom on Earth.]