In our newish house church experience, we've decided to make the Old Testament a focus of our Sunday mornings together. Most of the people in our group (including my wife and I) spent a lot of time applying NT scripture to our lives at the expense of the OT stories, so it's exciting for everyone to learn from the "left side of the Bible."
One of our greatest take-aways from reading through Genesis and Exodus (which took about 10 months) was God's perspective on man, his most important creation on earth. Because God has the ability to see a man's existence from before birth straight through to eternity after earthly death (referring to His omnipresence, omniscience, omnipotence)...
He is able to make very just decisions such as giving followers extra grace (ie., Abraham) or raining fire down upon them and killing every man, woman, child, and animal (as in Sodom and Gomorrah).
God hates sin, but it's a fruit issue and it's treated as such. What he seems to be even more concerned about in the heart and mind of His creation (man) is idolatry, the root of the sin problem. When man decides his idea of right and wrong is better than God's clearly articulated way of living for our best health and welfare, the aforementioned rain of fire is definitely in the weather forecast!
He views a lot of our earthly problems in the same way a loving parent comforts a child upset that they cannot eat candy before dinner because it will spoil their appetite for healthy food. The suffering I may experience here on earth will be but a sneeze in the big picture of my eternal life in Christ, and for that, He may choose not to heal someone on earth because it's but a sneeze no matter how big of a deal we think it might be.
The Trinity has always existed. Christ is seen throughout Genesis and Exodus!!! Lots of my house church peeps didn't fully grasp this until I showed them. Same with the Holy Spirit. All working as one to reconcile man to God.
He has created us all, but we are not all "God's Children." That would be automatic salvation and we must request to be adopted into His family through Christ. While this is a NT thing, we saw clearly that God's chosen people needed a Messiah in the worst way and still need to recognize that God provided one! No one can keep the basic ten commandments nor the thousands of Jewish laws.
When we start up our mid-week cell groups, it will be our New Testament focus. The Christ within me will minister to the Christ within you. This is happening ad-hoc now with time spent together, but it will be formalized in 2016.
This was an interesting thing to realize: Sunday mornings are OT and mid week groups are NT. Same God, different expression and experience!