Where does it say in the Bible that a woman who is living with her boyfriend can’t teach the youth?
I can’t think of one verse that speaks directly to this issue, but there are passages where we can learn that it would definitely be wrong for a woman living in sin to take the place of a teacher among the young. Let’s begin with instruction for a young woman. In 1 Timothy 5:14 the apostle Paul is speaking to young widows but it would apply equally to any young women. It says, “I will therefore that the younger women marry, bear children, guide the house, give none occasion to the adversary to speak reproachfully.” Scripture NEVER condones a young woman “living with her boyfriend,” for this is fornication, a serious sin that has serious consequences. The young woman should get married and have children, and then, and only then, will she be fit to “guide the house,” which means she has the solemn responsibility of directing and managing the household. In Titus 2:4-5 older women are instructed to “teach the young women to be sober, to love their husbands, to love their children, to be discreet, chaste, keepers at home, good, obedient to their own husbands, that the word of God be not blasphemed.” Here too we learn that young women should not live with their boyfriends but they should get married and have children, love their husband and children, and live a holy life. This qualifies them to be “keepers at home,” which means her sphere of responsibility is in the home. This confirms what we just read in 1 Timothy 5:14 where she is to “guide the house.” It doesn’t simply mean she does “housework,” but it includes the thought of caring for the spiritual welfare of her children. This means she is then in a position to “teach the young,” though when her husband is home he will be the spiritual leader of the family.
This should make it crystal-clear that it would be wrong for a single woman living in sin to teach the young. If one does attempt to do this, they are guilty of gross HYPOCRISY. When the Lord Jesus was here He often reproved the religious leaders of His day for teaching the Bible when they themselves were living in sin. In Matthew 23 he pronounced seven woes on them for this. In His first “woe” He said, in verse 13, “Woe unto you, scribes and Pharisees, hypocrites! For ye shut up the kingdom of heaven against men: for ye neither go in yourselves, neither suffer ye them that are entering to go in.” These self-righteous leaders rejected God’s salvation and yet they pretended to be teaching others how to be saved. The result was they were a stumbling block to others and neither they nor those they taught were saved. In Matthew 15:14 Jesus called them, “Blind leaders of the blind.”
In Romans 2 the apostle Paul echoed the sentiments of the Lord Jesus by rebuking Jewish hypocrites for trying to teach others to live holy lives when they themselves were living in sin. Listen to these strong words in verses 21-22, “Thou therefore which teachest another, teachest thou not thyself? Thou that preaches a man should not steal, dost thou steal? Thou that sayest a man should not commit adultery, dost thou commit adultery?” It is obvious that these so-called “teachers” had no business teaching men not to steal or commit adultery when they were guilty of those very things. So it would be equally wrong for a woman living in fornication to attempt to teach the youth to live a good and holy life. (172.7) (DO)