Well, of course you could take Psalm 23 in a Christian light, and apply it to your life that way.
But you don't have to be a Christian to reap the benefits from this psalm.
Maybe if we just looked at this psalm like Brooke looked at the world, then it would be easier to understand.
Psalm 23 is literally directions on how to live a great life.
(23:1) "I don't need a thing." --- We have everything and more. We need to take what we have and be happy with it. Moping about what you don't have, or what you want is not going to make you happy. We need to brighten up and look at the positive side of things
(23:4) "Even when the way goes through Death Valley..." --- Of course it isn't always going to be easy to be happy and cheerful, and of course bad things are going to happen, but if that's all you focus on, then what's the point? Pay attention to the good things, and let the bad things slip through your fingers.
(23:4) "Your trusy shepard's crook makes me feel secure." --- There's no need to be afraid. Don't fear what is unavoidable, but go through it with a smile.
(23:6)"Your beauty and love chase after me every day of my life." --- I guess this is a Christian point of view, but still, if you view life, knowing that even when you die, you're going to have eternity to look forward to, it's a lot more uplifting.
(1 Timothy 4:12)
"Don't let anyone look down on you because you are young, but set and example for the believers in speech, life, love, and purity."
David understood this verse and applied it to his life. Don't let anyone tell you you're too young to do something. David was barely 12 when he was anointed king and fought Goliath.
In modern society, Psalm 23 can be taken as a positive out-look on life. We don't have to look at it in a Christian point of view, but we can still apply it's good attitude to our lives.