Jesus Christ
IS within Jewish concepts. All original teachings in the N/T are through '
JEWS' (including Jesus Christ, Himself). Why would these Jews lie? Thousands of people (including Jews) witnessed the miracles and teachings of Jesus Christ. Thousands were fed from baskets that remained full.
The scriptures tell us, that the Israelites/Jews were 'hard-headed'. Perhaps God had separated some of these Israelites from each other, so that they could be turned to Christianity, while believing that they were in fact 'gentiles'. By waiting out approximately 800 years, all 'connections' to the lost tribes descendancy, could have easily been forgotten.
We know that God commanded that the Israelites celebrate the 'passover'. By having Jesus Christ crucified during the passover, when Christians celebrate the death and resurrection of Christ, they are also celebrating the passover (in God's view???).