"Is there any one single overriding principle that I can use to understand the Bible?"
Dear Wounded Pilgrim,
I do apologize for the somewhat rambling method of . Here's my attempt to try and put together my consideration regarding recovering our devotional reading of the Bible:
We need to learn to first study the Bible and bring that study with us as we read for devotion. (God speaks words to our minds; it is not some kind of mystical power that brings higher consciousness)
We must understand that intimacy with God is entirely because of the love of God for us. We don't meet God half-way. He loves us, and in the Gospel has saved us fully; we have been brought all the way back to God.
With these two principles understood we can now have a great time reading the Bible again and feel real good about it.
Here is an example. Psalm 15:1-5 asks, "Lord, who will dwell in your sanctuary," etc., and goes on to explain that only those whose behavior is up to snuff will be able to gain God's presence.
According to the "heart knowledge" devotional method we are to let the full weight of these words "speak to us" as if God is directly addressing us in this passage. What is the "spiritual teaching", the "spiritual meaning", and the "spiritual application" here?
If we are honest we are left with feeling very guilty and without hope of ever dwelling in God's presence. Of course, we can adopt the old overcomer's oath of trying harder tomorrow. This might actually be our application week after week (sound familiar?).
One other path is to pretend we are actually fulfilling the requirements and that God has made us His "special servants." We can see what this did for GG and those still faithful to him.
If instead we gird up the loins of our minds and bring some context to our reading we will escape the above difficulties. The one absolute overruling interpretive principle in understanding God's speaking to us in a particular verse is found in the Gospel. Jesus is called The Word of God and what He accomplished at the Cross is not only a wonderful work of salvation, it is a wonderful work of revealed truth. In that work is portrayed for us (Gal. 3:1) who God is, who we were, and what we now are in our salvation -- God is love, I was a hopeless sinner, and now I am completely His.
So as I now read Psalm 15, I recognize that the cross has brought me into God's presence because of the gift of God's righteousness. Even if we just used the context of the Psalms we can see David understood that God's righteous requirement had to be fulfilled by God Himself (Ps. 51, etc.), and not by some kind of overcomer devotional struggle. God has spoken directly to us in the Person and Work of Jesus Christ, and we are to think about that message and let it fill our hearts with peace and joy.
Whether you have time to read the Bible, or possibly because of your assembly past are disinclined to read it, you can just sit back and enjoy the thought that you are completely saved and that God loves you a whole bunch. Some will say this is "liberty to sin" and leads to an undisciplined life. I would answer it leads to an impassioned love for Him who has always been a dear friend to me and also to those little ones of His whom He has died for. Grace is always to "the praise of His glory".