2 Peter 2:17
These are springs without water, and mists driven by a storm, for whom the black darkness has been reserved.
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The 'these' that Peter is warning against, the springs without water, are the false prophets and false teachers who will, in their greed, work to exploit the people of God for their own purpose, typically either fame or fortune. Not only a problem then but indeed a growing one today as we get closer and closer to the Lord's return!
 
I flew as a crew member in the U.S. Navy during the tempestuous early and mid-1960's, mostly assigned to the far north-Atlantic Ocean. We were watching for the Russian missiles and submarines that posed the greatest danger of the day. I had quite a bit of survival training about how to deal with going down into those vast and cold waters if that ever became the case. I say all of that to mention the most important thing to deal with in such a situation is drinking water. You can be in thousands and thousands of square miles of water but as the Rime of the Ancient Mariner so clearly puts it, “Water, water everywhere, nor any drop to drink.”
 
Israel had known occasional droughts and faced the need for water even as they started their travels through the wilderness of Shur after crossing the Red Sea. They had found water, the waters of Marah, but they were not suitable to drink. The people grumbled at Moses, saying what shall we drink? God did a miracle to make the water palatable. {Ex.15:23-25}

And of course we should all be familiar with the amazing account of the prophet Elijah and the three-and-a-half-year long drought {1Kin.17} broken by his prayers as James tells us. {Jas.5:17-18} You can live quite a while with limited, or even no food, but you must have water to survive. The Lord Jesus who supplies all of our needs {Php.4:19} has said, "If any man is thirsty, let him come to Me and drink.” {Jn.7:37}
 
While the false prophets and teachers bring the promise of refreshing water, all they really bring is death! Jesus gives us the water of eternal life. Our Lord, speaking to the Samaritan woman at the well, said to her (and to us): “But whoever drinks of the water that I shall give him shall never thirst; but the water that I shall give him shall become in him a well of water springing up to eternal life." {Jn.4:14}

And it was Jesus Himself who said:
“Beware of the false prophets, who come to you in sheep's clothing, but inwardly are ravenous wolves.
    Many will say to Me on that day, 'Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?' And then I will declare to them, 'I never knew you; depart from Me, you who practice lawlessness.” (Matthew 7:15,22-23)
 
TEST EVERYTHING BY THE WORD OF GOD