But he shall receive an hundredfold now in this time…and in the world to come eternal life. – Mark 10:30

To speak against preaching the future as though it would make people neglect the present is absurd. It is as though somebody should say, “There, take away the moon, and blot out the sun. What is the use of them-they are not in this world?” Precisely so but take away the moon and you have removed the tides, and the sea becomes a stagnant, putrid pool. Then take away the sun, and light, and heat, and life; everything is gone. What the sun and moon are to this natural world, the hope of the future is to the Christian in this world. It is his light; he looks upon all things in that light and sees them truly. It is his heat; it gives him zeal and energy. It is his very life: his Christianity, his virtue would expire if it were not for the hope of the world to come. Do you believe, my brethren, that apostles and martyrs would ever have sacrificed their lives for truth’s sake if they had not looked for a hereafter? In the heat of excitement, the soldier may die for honor, but to die in tortures and mockeries in cold blood needs a hope beyond the grave. Would yon poor man go toiling on year after year, refusing to sacrifice his conscience for gain; would yon poor needle-girl refuse to become the slave of lust if she did not see something brighter than earth can picture to her as the reward of sin? O my brethren, the most practical thing in all the world is the hope of the world to come, for it is just this which keeps us from being miserable; and to keep a man from being miserable, let me say, is to do a great thing for him…The man who has a hope of the next world goes about his work strong, for “the joy of the Lord is our strength.” Through the Spirit of God, the hope of another world is the most potent force for the product of virtue; it is a fountain of joy; it is the very channel of usefulness. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0562.cfm