Christ's earthly ministry was directed at the "Lost Sheep of the House of Israel." Matthew 15:24 "But he answered and said, I am not sent but unto the lost sheep of the house of Israel." Christ made that perfectly clear!
After Christ was resurrected and Ascended to be seated at the right hand of the Father in Heaven, Peter, and the other Apostles continued Christ's ministry to the House of Israel.
After Christ was resurrected and Ascended to be seated at the right hand of the Father in Heaven, Peter, and the other Apostles continued Christ's ministry to the House of Israel.