Ah, grammar. What would we do without it? How, for example, would we be able to discuss intelligently Heb. 1:8? Should the text read, "Your throne is God forever and ever"? Or, "Your throne, O God, is forever and ever"?
Here the question is: What case is "God" (theos) in?
Most take it as being in the nominative case, which here is being used as a vocative. Say what? Never heard of "nominative" or "vocative" in my life!
Then, too, the passage is a quote from the Old Testament. It's from Psalm 45:6-7 in the LXX. There the words were originally addressed to God. But now God is the one speaking and he is addressing his Son as "God." But how can the Son of God be God? Isn't God one? (Enter the doctrine of the Trinity.)
By the way, this isn't the only place in the New Testament where Jesus is called "God." Other passages include Rom. 9:5, Tit. 2:13, John 20:28, 1 John 5:20, 2 Pet. 1:1, and the passage we'll be looking at tonight in Greek class -- John 1:1.
This is the meat of biblical interpretation.
No one can deny the importance of grammar. God doesn't want us to merely scratch the surface of his Word. He longs for us to dig deep, yes even in the midst of our busy lives. Like many of us, the readers of Hebrews had been Christians for many years. Little wonder Paul is exasperated with them. "By this time you should be far enough along in your Christian walk to be able help others grasp what God is saying in the Scriptures, but the truth is that you're still in kindergarten!"
For some of my beginning Greek students, tonight will be the first time they have ever really studied language or grammar, even things like the nominative and vocative cases. My prayer is that they would be challenged to think deeply about God's word, perhaps more deeply than ever before, and begin to make grammatical study a regular part of their lives. Oh, the difference that can make!