In 2 Kings 4 we read of a widow who owes a debt that she cannot pay. All she has is a pot of oil, not enough to make a difference (so she thinks). The creditor is really putting on the pressure, threatening that if she does not pay, he will be forced to take her sons as slaves.
Completely desperate for help she asks the Prophet, Elisha, what she should do. He tells her to go and borrow vessels from all of her neighbors; every empty vessel that can be found, bring it into the house. After collecting every vessel that could be found she was to take that pot of oil and pour it out into all the empty vessels.
The widow sent her sons to gather all the vessels in the village. It did not matter if they were large vessels or small vessels, ornate or plain. The only thing that mattered was that they be empty vessels. When they had finished gathering the vessels, she began to pour out the oil. As she poured, God miraculously multiplied the oil until every vessel was filled.
The oil represents the Holy Spirit. The empty vessels represent the empty souls of mankind, but notice, it took four types of vessels for the miracle to come to pass; it took a vessel of vision to see (Elisha), a vessel of faith to believe (widow), vessels of courage to do (sons), and empty vessels.
May God give us the vision to see, the faith to believe, and the courage to do.
The LORD is still filling empty vessels!