It's not a matter of convenience and I am not dropping the OT God, just the perception the Jewish people had, and some Christian groups have, of Him. Our perception of the OT God is that He is (by necessity) Christ-like and that if He appears not as the Christ of the Gospels then it is not a correct perception of God. It's not a matter of convenience but of what standard we use. In our case, we use Christ. I think that would be the definition of a Christian.
Well, the problem with this truncated view of God is that it means you follow One God revealed in One Person. That is NOT the definition of Christian. :) The correct standard is the totality of scriptures, which reveal three distinct Persons.
Christ is our image of God as we see Him, and as—we believe—God wants us to see Him. What makes us Christian is that we follow Christ as our standard of truth and life that leads to the invisible and incomprehensible Father whose essence is the same as that of Christ or the Spirit.
So, in essence, they are one and the same God. God the Father appear as something other than Chirst, or the Holy Spirit, and Christ cannot be anything other than like the Father or the His Spirit.
Anyone who calls Christ a "truncated" God (as if the wholeness of Divinity were not in Him, as if Chirst lacked perfection!) cannot, by defintion claim to be a Christian.
The correct standard is the totality of scriptures, which reveal three distinct Persons.
But there is hypostatic union only in one Person of God, the only one who could be seen and grasped, imitated and followed.
The Jews have a different image of a God, based on their "visions," and what not, which contains notions of Christ, but dimly. Look at what Jeremiah (32:40) has to say about God:
The OT God keeps the Jews to Himself, not by love, but by fear! Is that what Christ teaches His disciples?
I guess when Jeremiah wrote this, the changing of the hearts wasn't "in" yet. God had to resort to fear to keep His people in line. LOL!