Apocalypse Revealed # 497
497. And they have power over waters to turn them to blood. This symbolically means that people who turn away from these two essential elements falsify the Word's truths.
Waters symbolize truths (no. 50), and blood a falsification of the Word's truth (no. 379). Thus turning waters to blood symbolizes a falsifying of the Word's truths.
This has the same meaning as before, namely, that people who turn away from the two essential elements of the New Church cannot see anything but the falsities in which they are caught up, and if they use the Word to defend them, they falsify its truths.
Matthew 7:24-27
24
"Everyone therefore who hears these words of mine, and does them, I will liken him to a wise man, who built his house on a rock.
25
The rain came down, the floods came, and the winds blew, and beat on that house; and it didn't fall, for it was founded on the rock.
26
Everyone who hears these words of mine, and doesn't do them will be like a foolish man, who built his house on the sand.
27
The rain came down, the floods came, and the winds blew, and beat on that house; and it fell--and great was its fall."