Can a church elder or deacon be single / unmarried?

TL;DR:

Church elders and deacons do not have to be married, but they must live a life of sexual purity and faithfulness. Single leaders can serve God fully while honoring Him through chastity and integrity.

The Bible teaches that church elders and deacons do not have to be married, but they must live lives marked by sexual purity and faithfulness. Single men can dedicate themselves more fully to service, which is a blessing. Still, they must honor God by maintaining chastity and fidelity. Overall, a man serving as an elder must be a “one-woman man” who leads with integrity and upholds purity—chastity in singleness and faithfulness in marriage. Whether single or married, leaders’ commitment to purity and faithfulness models Christlike character and enables them to guide the church with credibility and moral authority. Holiness, integrity, and wholehearted devotion to God are essential aspects of leadership, regardless of marital status.

from the old testament

The position of church elder or deacon is not mentioned in the Old Testament.

from the new testament

First Timothy 3:12 and Titus 1:6–7 both say that elders must be "the husband of one wife." Like a few other passages in Paul's writings, these statements seem difficult to interpret. Does Paul mean that elders and deacons must be husbands, or that if they are husbands, they must only have one wife? Despite the problematic English translations, the Greek is clear: the elder must be a "one-woman man." He must be biblically married to only one woman, and he must be faithful to her. His sexual purity must be above reproach. He cannot lead the congregation in following God if he has problems with fidelity.
This call to fidelity applies even if the man is not yet married. Single men can hold to the spirit of being a "one-woman man" by maintaining sexual purity as a single man. Before he gets married, he can be faithful to his future wife by not sleeping with anyone. If his wife has passed away, he is no longer bound to her (1 Corinthians 7:39), but he can still be a "one-woman man" by maintaining sexual purity until he marries again.
What about men who are not married and have no intention to ever marry? Taking the Bible as a whole, it's obvious that a present or future marriage is not required for all elders. Jesus was never married, and 1 Corinthians 7:8 indicates Paul wasn't, either. First Corinthians 7:32 explains that single men can be even more dedicated to service to God.

implications for today

The call to purity and fidelity are important, especially for those who would like to one day hold a leadership position in the church. God calls all of us to chastity before marriage and fidelity in marriage for our protection and because all good things require protection. Sexual purity guards our hearts, minds, and bodies from the emotional, spiritual, and relational consequences of sin, helping us maintain healthy relationships and a clear conscience before God. Fidelity in marriage strengthens the covenant relationship, building trust, intimacy, and stability. Living in purity strengthens our relationships and reflects God’s character. For those in leadership, living a life of purity and faithfulness provides credibility, moral authority, and a consistent witness, enabling them to guide others with integrity and Christlikeness.

understand

An elder can be married or unmarried.
An elder must be a “one-woman man.”
An elder must be devoted to God and purity, whether married or unmarried.

reflect

How are you cultivating purity and faithfulness in your life today, whether single or married?
How do you evaluate and cultivate your character and integrity as preparation for leadership?
How do you support those in leadership to uphold purity and faithfulness?

engage

What do the requirements for an elder reveal about the importance of one’s character in leadership?
How can single and married leaders each uniquely reflect Christlike character in their service to the church?
How does the emphasis on character over marital status influence our understanding of leadership in God’s kingdom?