Water generally represents “natural truth,” or true concepts about day-to-day matters and physical things. Since all water ultimately flows into the seas, then, it follows that a sea represents a huge agglomeration of such natural truths -- usually all of the natural truth a person has, or all the natural truth a church has. Water in the sea mixes freely, and is easily stirred up by winds and currents. This is also true of the concepts we hold about natural things -- they are not all related to each other, and when relationships do exist they usually can change without damaging the concepts themselves. Many of the concepts are easily disputed, and arguments can arise like waves on the ocean -- generally with little effect other than a mixing of waters. But the sea also offers great bounty. We draw fish from it (spiritual food), float ships (doctrinal systems) on it, bathe in it (using true concepts to purify ourselves), and the water that evaporates from it and falls as rain (purer forms of truth that can attach to desires for good) makes life possible.

664. Verse 11. And after the three days and a half, signifies when it is finished, thus the end of the old church and the beginning of the New Church. This is evident from the signification of "the three days and a half," as being fullness and completion as to the end of the old church, when there is the beginning of the New Church (See above, n. 658). It is said "after the three days and a half" because in the Word "days" signify states, here the last state of the church; for in the Word all times, as "hours," "days," "weeks," "months," "years," "ages," signify states, as here the last state of the church, when there is no longer any good of love or truth of faith left. Because "days" signify states, and the establishment of the Most Ancient Church is treated of in the first chapter of Genesis, and it becomes established successively from one state to another, it is there said:

That there was evening and there was morning the first day, the second, the third, the fourth, the fifth, and the sixth days, even to the seventh, when it was finished (Genesis 1:5, 8, 13, 19, 23, 31; 2:2);

and the "days" there do not mean days, but the successive states of the regeneration of men at that time, and the consequent establishment of the church with them. So also elsewhere in the Word.