Knowing that of the Lord ye shall receive the reward of the inheritance: for ye serve the Lord Christ. – Colossians 3:24

Do you know what is the deliciousness of work? For although we must complain when people expect impossibilities of us, it is the highest enjoyment of life to be busily engaged for Christ. Tell me the day I do not preach, I will tell you the day in which I am not happy; but the day in which it is my privilege to preach the Gospel, and labor for God, is generally the day of my peaceful and quiet enjoyment after all. Service is delight. Praising God is pleasure. Laboring for Him is the highest delight a mortal can know. O, how sweet it must be to sing His praises, and never feel that the throat is dry! O, how blessed to flap the wing for ever and never feel it flag! O, what sweet enjoyment to run upon His errands, evermore to circle round the throne of God in heaven while eternity shall last, and never once lay the head on the pillow, never once feel the throbbings of fatigue, never once the pangs that admonish us that we need to cease, but to keep on for ever like eternity’s own self—a broad river rolling on with perpetual floods of labor! O, that must be enjoyment! That must be, indeed, a heaven, to serve God day and night in His temple! But you have served God on earth and have had foretastes of that. I wish some of you knew the sweets of labor a little more, for although labor breedeth sweat, it breedeth sweets too—more especially labor for Christ. There is a satisfaction before the work; there is a satisfaction in the work; there is a satisfaction after the work, and there is a satisfaction in looking for the fruits of the work; and a great satisfaction when we get the fruits. Labor for Christ is, indeed, the robing-room of heaven; if it be not heaven itself, it is one of the most blissful foretastes of it. Thank God, Christian, if you can do any thing for your Master. Thank Him if it is your privilege to do the least thing for Him, for remember in so doing He is giving you a taste of the grapes of Eshcol. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/0989.cfm