You should not assume
Well, maybe its ok, I'm not saying you must not. But your wrong in that I was going to say that - except now that you bring it up....... Just messing with you.
However, what I was going to bring up after I confirmed that you believed they are both from Christ, is this;
Gal 1:6-8
I am astonished that you are so quickly deserting him who called you in the grace of Christ and are turning to a different gospel—
not that there is another one, but there are some who trouble you and want to distort the gospel of Christ.
But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed.
There is only one Gospel of Christ. Singular. There is no getting around this. People were preaching that there was different 'good news' that came from Christ.
On the outside this looks fine. I mean, good news is good news, right? But on the inside, it distorts the truth. Truth can only be singular. If you add anything to truth then it is no longer truth.
The idea that they would have accepted Christ as their Messiah, when He came, is not a good idea. God had no intentions of them accepting Christ as their Messiah. If, there was any possibility, of the Nation of Israel to accept Him and the Kingdom be set up at that time - then the prophets of the OT would have been false, and nothing would have been been able to be true.
Christ was crucified before the world was made. Before - not after. Christ had to die, therefore there is only one Gospel - and that is His sacrifice for us.
I want to say, in as most loving way as possible, that this is where dispensationalism can really mess up a persons theology. All it does is add confusion to the simple truth of God.