New International Version
12 If you hear it said about one of the towns the Lord your God is giving you to live in 13 that troublemakers have arisen among you and have led the people of their town astray, saying, “Let us go and worship other gods” (gods you have not known), 14 then you must inquire, probe and investigate it thoroughly. And if it is true and it has been proved that this detestable thing has been done among you, 15 you must certainly put to the sword all who live in that town. You must destroy it completely,[a] both its people and its livestock. 16 You are to gather all the plunder of the town into the middle of the public square and completely burn the town and all its plunder as a whole burnt offering to the Lord your God. That town is to remain a ruin forever, never to be rebuilt,
A town that had completely rejected God was to be destroyed. This way the nation would not be led astray. Action was not to be taken until the rejection was proven true. If you hear of a friend or family member or a group of people who has wandered from the Lord, check the facts and find the truth first. There is the right time to help the wayward and be sure you have your facts straight. Then, take action.
Spirit and Truth