How does God know everything?

This is truly a questions that we will all have until the end of time...and even beyond. Well I've been reading this bible in a year program and i was reading Matthew, Specifically verses 23-25. Basically Jesus telling us of the end of time, and a few parables about it. In 25:31-46 it says this

31"But when the Son of Man comes in His glory, and all the angels with Him, then He will sit on His glorious throne.
32"All the nations will be gathered before Him; and He will separate them from one another, as the shepherd separates the sheep from the goats;
33and He will put the sheep on His right, and the goats on the left.
34"Then the King will say to those on His right, 'Come, you who are blessed of My Father, inherit the kingdom prepared for you from the foundation of the world.
35'For I was hungry, and you gave Me something to eat; I was thirsty, and you gave Me something to drink; I was a stranger, and you invited Me in;
36naked, and you clothed Me; I was sick, and you visited Me; I was in prison, and you came to Me.'
37"Then the righteous will answer Him, 'Lord, when did we see You hungry, and feed You, or thirsty, and give You something to drink?
38'And when did we see You a stranger, and invite You in, or naked, and clothe You?
39'When did we see You sick, or in prison, and come to You?'
40"The King will answer and say to them, 'Truly I say to you, to the extent that you did it to one of these brothers of Mine, even the least of them, you did it to Me.'
41"Then He will also say to those on His left, 'Depart from Me, accursed ones, into the eternal fire which has been prepared for the devil and his angels;
42for I was hungry, and you gave Me nothing to eat; I was thirsty, and you gave Me nothing to drink;
43I was a stranger, and you did not invite Me in; naked, and you did not clothe Me; sick, and in prison, and you did not visit Me.'
44"Then they themselves also will answer, 'Lord, when did we see You hungry, or thirsty, or a stranger, or naked, or sick, or in prison, and did not take care of You?'
45"Then He will answer them, 'Truly I say to you, to the extent that you did not do it to one of the least of these, you did not do it to Me.'
46"These will go away into eternal punishment, but the righteous into eternal life."

Now people interpret this verse so many ways...I don't want to get into that because well...you wouldn't want to read everything i could say about this, but i just wanted to say something. Verse 35-36 really hit me. Not because i think that you need to do works to gain salvation...because you don't. Works should come naturally out of you faith in God...which is all from God...another long topic that many would love to discuss...it was more of the praticle since though of this. Just simply helping people because of what God has done for you...I can't count how many times i've driven by people and just ignored them...even when they really needed help. On Sunday after church God gave me an oppurtunity to live this out. A man was broken on the freeway and was pushing his truck...a small UHaul basically...well i pulled over to help. And he seemed very apprcitive. It was a hot afternoon and the man was probablly in his late 50's or so...As i drove by this verse was tugging at me to stop...and like i said not because i think thats how i'll get into heaven...but because of what Jesus has done for me...and what he has given me. Like i said he was very appriciative of the help and even gave me a card with his business saying if i needed anything to let him know...that was a nice gestur...i would never do something like that for something in return but it was nice. So anyways how did God know that verse was tugging at my heart and how did he set it up that i could help someone in need? well its obviously him who did all this...but its still crazy to think...and like i said one more time...I don't think what i did ment that i'm better or that i have gain a lil more salvation...but the joy of just helping someone out...because Jesus in turn helped me...makes it good!