a "sheep", as always known to be a meek and humble animal, portrays the Christians (or the follower of Christ) and that Jesus stand as their good Shepherd. "I shall not want" could mean that "there's nothing I need when the Shepherd (Jesus) is upon us." consider this also: "The Lord is my light and salvation, whom shall I fear?" (Psalm 27:1) :)

Yes, a bit tricky ne. :) It's not like "The Lord is a shepherd (that) I shall not want;" but rather "The Lord is my shepherd; I shall not want (for anything)." 'To Want' (transitively) usually expresses a desire to do/have X. Like: "I want to go read;" "I want to go home." "Ï want to answer a few questions on italki." Or it can mean 'to lack.' As in: "This cake wants sugar." Another way of putting the latter is: "This cake is in want of sugar." Intransitively, it means 'to have need.' Like "I shall not want." It can also mean 'to lack' here. As in: "Sensei put him to a small Katakana test, but he was soon found wanting." Meaning: he was found to lack the required proficiency/knowledge, etc. So, essentially, you can go in both directions with "I shall not want." Even though the vast majority of people read it as "I shall not want for anything," the World English Bible, for instance, translates it as follows: "Yahweh is my shepherd: I shall lack nothing." And that rendition is also not wrong. Actually, the original Hebrew 'chacer' also means 'to lack, be without, decrease, be lacking, have a need.' So, that solves nothing. :) Oh, and Jesus as a Shepherd is a common metaphor throughout the New Testament; see for example: http://www.2pi.info/bible/studies/ShepherdStudy/GoodShepherd.html

Psalm 23 : The author of this psalm makes no request of God, but simply throws himself on the Lord’s care with complete trust. Neither does he complain about his circumstances, though the psalm does note various perils, some of which may have existed in the author’s past. The text uses various images to depict God’s care for beloved people. The first and best known is of the Lord as a shepherd. This image continues through verse 4, though some see a second image, as a guide, in verse 4. The final image is of a banquet at which the author is hosted by God, and at which he is protected from his enemies. The writer is confident of rest, food, renewal, comfort, protection, “goodness and mercy.” He describes circumstances when all is well, and those when danger is near. In each case God is trusted absolutely.

"I shall not want" means "I shall not be in need, I shall not be lacking anything, I shall not be very poor" because the Lord provides for my needs just like a shepherd finds rich pasture for his sheep. You should research the meaning of words beyond the most common one.

Sheep = follower = no brain of their own :0