For David, after he had served his own generation by the will of God, fell on sleep, and was laid unto his fathers, and saw corruption. – Acts 13:36

What is it to serve our generation? I answer, it is to perform the common duties of life as David did. David was the son of a farmer, a sheep-owner, and he took first of all to the keeping of the sheep. Many young men do not like to do the common work of their own father’s business. You do not want to drudge, you say, you want to be a king. Well, there are not many openings in that line of business; and I shall not recommend anyone to be eager to enter them if there were. “Seekest thou great things for thyself? Seek them not.” Before David swayed the sceptre, he grasped the shepherd’s crook. He that at home cannot or will not undertake ordinary duties, will not be likely to serve his age…In the midst of the routine of daily life, we should, by diligence in duty, prepare for whatever may be our future opportunity, waiting patiently until it comes. Look at David’s occasion of becoming famous. He never sought it. He did not go up and down among his sheep, sighing and crying, “Oh, that I could get away from this dull business of looking after these flocks! My brothers have gone to the camp; they will get on as soldiers; but here am I, buried among these rocks, to look after these poor beasts.” He was wiser than that; he quietly waited God’s time. That is always a wise thing to do. If you are to serve God, wait till he calls you to do His work; He knows where to find you when He wants you; you need not advertise yourself to His omniscience…If you want to serve the church and serve the age, beloved friend, be wide awake when the occasion comes. Jump into the saddle when the horse is at your door; and God will bless you if you are on the look-out for opportunities of serving Him. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2243.cfm