Dear children, this is the last hour; and as you have heard that the antichrist is coming, even now many antichrists have come. This is how we know it is the last hour. They went out from us, but they did not really belong to us. For if they had belonged to us, they would have remained with us; but their going showed that none of them belonged to us. –1 John 2:18-19

Sand is inexpensive and heavy, which is why sandbags are used for jobs like protecting vehicles and buildings during bombings or storms, or balancing the total weight on a boat. When you use sandbag as a verb, it either means to protect with sandbags or to deceive or coerce someone to get something you want. When you pretend that you’re terrible at basketball just so you can beat your cousin in one-on-one, you sandbag her. –Vocabulary.com