NT Wright says:
'What then is this vindication, this dikaiosis? It is God’s declaration that a person is in the right; that is, (a) that their sins have been forgiven, and (b) that they are part of the single covenant family promised to Abraham.'
Many Muslims get hung up over the Jewish terminology in the Bible. Phrases like 'salvation is from the Jews' (John 4:22) are particularly difficult. Why 'from the Jews'? Why not 'from the Arabs'? Any Muslim would be far happier with the latter statement.
But if NT Wright is correct, then justification, or vindication as Wright calls it, is not only to do with our individual relationship with God, but also to do with our membership of the community of believers that goes right back to Abraham. And we need to remember that Abraham was the father, in physical terms, of not only Isaac but of Ishmael too (the ancestor of the Arabs). In spiritual terms he is the father of us all. Either way the Arabs are included in the grace of the gospel, and need not fear exclusion on the basis of race. The only condition of becoming a believer is being able to state, with Paul, that 'Jesus is Lord'. Since Muslims acknowledge Jesus as a prophet, it is only a small step to also believe in him as king.
The more extreme followers of a militaristic form of Islaam need to be careful, however.
'The united multi-ethnic church is a sign of God’s healing and remaking of the cosmos and also thereby a sign to Caesar and his followers that his attempted unification of the world is a blasphemous parody.' (ibid.)
The attempted unification of all earthly powers into an Islaamic Ummah ('community') with Sharia being enforced on all citizens is a modern-day parody of the multi-ethnic people of God. This, we must resist, by boldly stating 'Jesus is Lord'. No earthly leader, king, or system is above Jesus.