O us, perhaps this is a strange passage. However, it is an important one. Jesus quoted from this psalm (as is recorded in John 10:34-36) in His defense of His claim of deity. Presumably, He meant that to claim to be a son would (or should) seem to be less of an offense than applying the name of the original.
It is true that the use of the word "god" in reference to men of God appears to us to be unusual to say the least. But as Jesus pointed out, the Spirit of God chose that usage. He had a purpose and a point. Jesus wasn't exalting humanity beyond our rightful place, He was demonstrating the incongruity of the legalism of the Jews to whom He was attempting to minister. They were condemning Him for a claim that in some ways should have been less shocking than words from the very law that they claimed to revere above everything else (John 5:39). And, as we know... His claim was actually true, so any criticism directed His way in that regard was absolutely unjustified.
But wait, look back at the use of the label "gods" to describe any humans. What was the actual and original point? We are, after all, created beings. There is only one God. There are 4 issues that we can point to in trying to discover God's motive for using an exalted term such as this in reference to His mere creations. First of all, He did make us in His image. Bearing His likeness is no light matter (Genesis 9:6 & James 3:9). Secondly, some among us are called of God to deliver His words to the rest of us (Romans 10:15 & Isaiah 52:7). Thirdly, God has endowed some among us with authority over others (Romans 13:1-2). As such, we function as His representatives. Forth, finally and most obviously in our text, we are the children of God (1stJohn 3:2, Luke 3:38 & Psalm 82:6).