'Waters' particularly signify the spiritual parts of a person, or the intellectual aspects of faith, and also their opposites.

'The waters above the firmament,' as in Genesis 1:7, signify the knowledges in the internal self, and 'the waters beneath the firmament' signify the knowledges of the external self.

'Waters,' as in Ezekiel 47:9, refer to the New Jerusalem, and they signify spiritual things from a celestial origin.

'Many waters,' as in Revelation 17:1, signify truths of the Word adulterated. 'Waters' or 'rivers' signify spiritual, rational, or scientific things pertaining to truth.

'Waters … that go softly,' as in Isaiah 8:6-7, signify spiritual things, and 'waters … strong and many,' signify falsities.

'Waters,' as in Psalms 104:3, signify divine truths.

'Waters' signify truths in the natural self, and in the opposite sense, falsities.

'The waters were dried up from off the earth,' as in Genesis 8:7, signifies the apparent dissipation of falsities.

(Referencias: Apocalypse Explained 17; Apocalypse Revealed 50; Genesis 8)

It's pretty easy for most people to read the Bible and get a sense for what “sheep” means without any help. They are simple, peaceful, trusting and willing to be led, and the image of the Lord as both a shepherd and a lamb reinforces a sense of innocence. And indeed, sheep represent people who desire what is good, to be good, and to do what is good. Arriving at such a state requires the work of a lifetime -- learning what's right, setting aside what's evil, determining to follow the Lord -- but once we arrive at such a state, we can be cared for by the Lord in peace.