Should pastors or ministers retire at a certain age? If so, when, and if not, why not?
Moses was apparently fit to cross over into the Promised Land with Israel, but God told Moses he would not enter into the land because he had disobeyed God earlier (Num 20). God told Moses, “This is the land of which I swore to Abraham, to Isaac, and to Jacob, ‘I will give it to your offspring.’ I have let you see it with your eyes, but you shall not go over there” (Deut 34:4), so “Moses the servant of the LORD died there in the land of Moab, according to the word of the LORD, and he buried him in the valley in the land of Moab opposite Beth-peor; but no one knows the place of his burial to this day” (Deut 34:5-6). It wasn’t because of Moses’ age or his diminishing skills that he was “gathered unto his people” (Deut 32:50), because “Moses was 120 years old when he died. His eye was undimmed, and his vigor unabated” (Deut 34:7). The only reason Moses could not cross over into the Promised Land was because God told him, “you broke faith with me in the midst of the people of Israel at the waters of Meribah-kadesh, in the wilderness of Zin, and because you did not treat me as holy in the midst of the people of Israel” (Deut 34:51). Moses would get to see it, but not cross over into it (Deut 34:52). Today of course, Moses is in the Promised Land, or in the presence of Jesus Christ, which is far, far better. We know that from the Mount of Transfiguration experience where Jesus was with Elijah and Moses (Matt 17), so neither Moses, Aaron, or Elijah “retired” from their ministry due to age. God simply ended it. Now it was time for Joshua’s leadership.
When God established the sacrificial system for the nation of Israel, He instituted finite details about how to carry it out. This included the priestly functions, and just about every minute detail you can think of. The priests were extremely careful when performing their duties. One mistake could cost them their lives, but God placed an age limit on some of those who did the priestly duties. The Book of Numbers 8:23-26 says that “the Lord spoke to Moses, saying, “This applies to the Levites: from twenty-five years old and upward they shall come to do duty in the service of the tent of meeting. And from the age of fifty years they shall withdraw from the duty of the service and serve no more. They minister to their brothers in the tent of meeting by keeping guard, but they shall do no service. Thus shall you do to the Levites in assigning their duties.” The priests didn’t voluntarily retire because God had commanded them to “withdraw from the duty of the service and serve no more” at age fifty, and they could still be reassigned to another service, but since priests at this age and beyond have passed their prime of life, It could be God’s showing them mercy. This could be due to the fact that the Levitical Priesthood duties required an extreme exactness like no other. Even a minor infraction could result in death. There are several occasions where the priests profaned their offering to God by presenting “strange fire” (Lev 10) and “fire came out from before the LORD and consumed them, and they died before the LORD” (Lev 10:2). God takes His holiness seriously, and that of His people.
I could not find any Bible verses that fit in with the American idea of working to a certain age only to retire and quit working. Moses kept working even after God told him that he wasn’t going into the Promised Land. Besides, retirement is not a biblical model of servanthood that was taught by Christ (Matt 25:25-36, 40). I truly believe that as long as we are drawing breath, God is not finished with us. He expects us to glorify Him all the days of our lives (Psalm 115:1). There is nothing that says that it is sinful for a man or woman to retire at a certain age, but it is a huge waste of their time, talents, and treasure. Retirees are one of the greatest untapped resources of wisdom there is; a deep well of experience to draw upon. And I have never read of any account where any of the Apostles retired. The Apostle Paul said, “I do not account my life of any value nor as precious to myself, if only I may finish my course and the ministry that I received from the Lord Jesus, to testify to the gospel of the grace of God” (Acts 20:24). Paul insisted he would finish his “course and the ministry,” so there is not even a hint of him retiring. There are no rocking chairs found in the Scriptures.
We have two very old pecan trees and a black walnut tree in our yard that are well over a hundred years old, and they are still producing pecans and black walnuts, and we’ve been told that they’re about as good as any they’ve tasted. The point is, God is faithful to us, even into our senior years. The psalmist writes, “I have been young, and now am old, yet I have not seen the righteous forsaken or his children begging for bread” (Psalm 37:25). I admit, it’s been pretty close at times, but God has never forsaken us. I am not saying that retirees shouldn’t enjoy their retirement, but being fully devoted to it, is not prescribed for believers. Only for those who fall away or are carried away by the deceitfulness of riches (Mark 4:19; 1 Tim 6:9-10).
Luke 12:16-21 records the only time I could find where someone actually retired, but it turned out badly. Jesus spoke a parable and said, “The land of a rich man produced plentifully, and he thought to himself, ‘What shall I do, for I have nowhere to store my crops?’ And he said, ‘I will do this: I will tear down my barns and build larger ones, and there I will store all my grain and my goods. And I will say to my soul, “Soul, you have ample goods laid up for many years; relax, eat, drink, be merry.”’ But God said to him, ‘Fool! This night your soul is required of you, and the things you have prepared, whose will they be?’ So is the one who lays up treasure for himself and is not rich toward God.” This man could retire in leisure and luxury, but that’s presuming on God’s goodness, since the Lord could take them any time. Jesus said “For what will it profit a man if he gains the whole world and forfeits his soul? Or what shall a man give in return for his soul” (Matt 16:26). The loss of the rich man’s wealth was nothing in comparison to the cost of his own soul.
The day may come when a pastor cannot read the Scriptures any more, or he can’t hear the sermons, or he can’t walk to service anymore, but that’s God’s sovereignty, not the person choosing to retire. If you are retired or will be retiring soon, congratulations, but why not volunteer at a homeless shelter as a way to be the hands and feet of Christ? How about serving as a reading volunteer in the local public school? How about donating blood more often, or serving in a church ministry? Perhaps you could spend more time visiting and praying for the sick in the hospitals or cheering up the many lonely souls in nursing homes. Even though I’ve reached the retirement age, I’ve got my “second wind” and I’m not slowing down. I plan on working, serving, visiting, praying, loving, and whatever else the Lord can use my wife and I for, for as long as He wills. My wife stands next to me, and is part and parcel of this ministry, so as long as I’m drawing a breath, God is not done with me, so why should He be done with you? You are still breathing, aren’t you?
Here is some related reading for you: How Should Christians Retire? How Should they Spend their Retirement? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.