Dear friend, if you look at the text of the Covenant between God and the Jews it in no place mentions accepting a Jewish Carpenter as their Messiah. In fact, in no place inside of the cannon of the Torah is a Messiah mentioned in any form.
Believe me, this path only leads to disillusionment for Christians. Replacement Theology is pernicious and evil. This is not God's way.
In fact, lets listen to Jesus of Nazareth's words on this subject.
One of the scribes came near and heard them disputing with one another, and seeing that [Jesus] answered them well, he asked him, "Which commandment is the first of all?"
Jesus answered, "The first is, 'Hear, O Israel: the Lord our God, the Lord is one; you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength.'
The second is this, 'You shall love your neighbor as yourself.' There is no other commandment greater than these."
Then the scribe said to him, "You are right, Teacher; you have truly said that 'he is one, and besides him there is no other'; and 'to love him with all the heart, and with all the understanding, and with all the strength,' and 'to love one’s neighbor as oneself,'—this is much more important than all whole burnt offerings and sacrifices."
This is the core of Jewish faith and the wall that bars us from ever accepting an intermediary, for this is a promise each Jew makes at the foot of Mt. Sinai for themselves directly to God in his presence. Jews may fall or falter, but God willing these are the last words on our lips, Shema Israel, Adonai Elohenu, Adonai Echad.
Build as you would like on this foundation but you can not build anything unless this foundation stands.
You explained the Jewish faith to me. Thank you. This article explains mine. I merely pointed out that Replacement theology is not self-contradictory for a Christian; it is, in fact, the only plain reading of the Gospels.