Did you every buy something, bring it home and realize what you bought was a big waste of money? This "Diet Water" is a good example. Those who deceive will eventually pay for what they do... and here is an example from the book of Acts...
Acts, Chapter 8
5 Philip went down to the city of Samaria, and proclaimed to them the Christ. 6 The multitudes listened with one accord to the things that were spoken by Philip, when they heard and saw the signs which he did. 7 For unclean spirits came out of many of those who had them. They came out, crying with a loud voice. Many who had been paralyzed and lame were healed. 8 There was great joy in that city.
9 But there was a certain man, Simon by name, who used to practice sorcery in the city, and amazed the people of Samaria, making himself out to be some great one, 10 to whom they all listened, from the least to the greatest, saying, “This man is that great power of God.” 11 They listened to him, because for a long time he had amazed them with his sorceries. 12 But when they believed Philip preaching good news concerning the Kingdom of God and the name of Jesus Christ, they were baptized, both men and women. 13 Simon himself also believed. Being baptized, he continued with Philip. Seeing signs and great miracles occurring, he was amazed.
14 Now when the apostles who were at Jerusalem heard that Samaria had received the word of God, they sent Peter and John to them, 15 who, when they had come down, prayed for them, that they might receive the Holy Spirit; 16 for as yet he had fallen on none of them. They had only been baptized in the name of Christ Jesus. 17 Then they laid their hands on them, and they received the Holy Spirit. 18 Now when Simon saw that the Holy Spirit was given through the laying on of the apostles’ hands, he offered them money, 19 saying, “Give me also this power, that whomever I lay my hands on may receive the Holy Spirit.” 20 But Peter said to him, “May your silver perish with you, because you thought you could obtain the gift of God with money! 21 You have neither part nor lot in this matter, for your heart isn’t right before God. 22 Repent therefore of this, your wickedness, and ask God if perhaps the thought of your heart may be forgiven you. 23 For I see that you are in the gall of bitterness and in the bondage of iniquity.”
24 Simon answered, “Pray for me to the Lord, that none of the things which you have spoken happen to me.”
Simon thought he was somebody, but even he recognized true power when he saw it. But, instead of just submitting to God, he wanted to buy his way into God's power. And he was condemned for it. Fortunately, he had enough sense to realize his stupidity to the point of repentance, with his statement of verse 24 being proof of this. The point of all this is... be honest in all that you do- and be careful how you act towards God, for HE holds your eternal destiny in his hands.