As I have said, we are all dispensationalists at heart, it is just the extent of it.
We were all brought up reading the bible and there is a clear blank page that divides the Old Testament and the New Testament. Thus, we grew up being taught that the NT applies to us specifically, but the OT is for us to learn from, but the OT applied to the Jews.
However, when it comes to books in the NT, only those who lean even more towards dispensationalism will accept that certain books are instructions mainly to the Jews, and do not apply to the Gentile Church directly.
I can see that you are not one of them, and that is fine. All of us are still saved because of the Gospel of Grace, which is putting our faith in the death burial and resurrection of Jesus Christ.
And I would add that the NT does not begin until the death of the testator, not with Matthew 1. A transition took place after His death as the message changed from being Jewish in nature to the Gentiles through the apostle Paul. And then back to the Jews after the rapture of the Church which takes place in Paul’s epistles.