Psalm 82

God takes His stand in His own congregation:

He judges in the midst of the rulers (v.1).

God's court has convened.  He is judging the rulers of Israel who have failed to judge justly.

How long will you judge unjustly,

And show partiality to the wicked? (v.2)

Selah.

Take a look at II Chronicles 19:6-7:  And he said to the judges, "Consider what you are doing, for you do not judge for man but for the Lord who is with you when you render judgement.  Now the let the fear of the Lord be upon you; be very careful what you do for the Lord our God will have no part in unrighteousness or partiality, or the taking of a bribe."

Vindicate the weak and fatherless;

Do justice to the afflicted and destitute.

Rescue the weak and needy;

Deliver them out of the hand of the wicked (v. 3-4).

Consider Deut. 17-22:  

You shall not pervert the justice due an alien or an orphan (people who don't "belong", people without an advocate?), nor take a widow's garment in pledge.  

But you shall remember that you were a slave in Egypt (I am a sinner without hope), and that the Lord your God redeemed you (through the death of His only Son) from there; therefore I am commanding (not a suggestion, or a guideline but a command to us from Holy God) you to do this thing.  

When you reap your harvest in your field and have forgotten a sheaf in the field, you shall not go back to get it; it shall be fore the alien, for the orphan, and for the widow, in order that the Lord your God may bless you in all the work of your hands.  (When I can budget and live on less, have extra time to volunteer, He commands me to give the leftovers to the alien, orphan & widow, instead of saving for that National Geographic Photography Workshop in New Mexico I dream of attending... or perhaps it could be instead of saving all my extra change for that, I save it up for the Word and Deed offering that benefits the needy in our congregation & community?)

When you beat your olive tree, you shall not go over the boughs again; it shall be for the alien, for the orphan, and for the widow.  (God is repeating this over and over... I wonder why?)

When you gather the grapes of your vineyard, you shall not go over it again; it shall be for the alien, for the orphan, and for the widow.  And you shall remember that you were a slave in the land of Egypt; therefore  I am commanding you to do this thing (remember from whence I have come/ how far He continues to bring me).

They do not know nor do they understand;

They walk about in darkness;

All the foundations of the earth are shaken.

I said, "You are gods,

And all of you are sons of the Most High.

Nevertheless you will die like men,

And fall like any one of the princes."

The Psalmist, if you interpret "they" as the Israelites, is saying that they are clueless, they don't know God, and they are not interested in good (see Jer. 4:22, 22:15-17).  Those who rule here on earth must keep in mind that they rule at His pleasure (Romans 13:1) and as His representative.  Here God is stating that even though they are His chosen, these folks have failed to represent Him as He commanded and they will face His judgement as a result.

Arise, O God, judge the earth!

For it is Thou who dost possess all the nations.

God is in charge of all nations.  He will come to judge the entire world.  Be ready.

There is much much more in this Psalm.  Jesus refers to this Psalm in John chapters 9 & 10.  Let me know what you find...