During intense persecution by the Jews at the time, the true Christians loved their enemies and prayed that God would have mercy on them. They would rather face death than deny Jesus Christ. This is the love that Christ taught His followers to have.
Elijah will come before the first and second coming of Christ. Elijah will be the precursor to the second coming of the glorious return of Jesus Christ.
Jesus is the new covenant, he is the new law. Doing the Torah to the letter is what was done away with. The spiritual Israel are the followers of these spiritual laws.
Christ is the end of doing the Torah in the letter, the literal, no longer a physical circumcision but a spiritual one, no longer a physical sabbath but a spiritual. Justin Martyr explains how even the Jews tried to alter scriptures that had to do with the prophecies of Christ. The letter of the law was given to the people because of the hardness of their heart, walking in the letter will not bring holiness or righteousness. We are to follow the spiritual and eternal decrees.