What, then, is the advantage of being a Jew? Or what is the value of circumcision? — Romans 3:1

This is the argument that silences every doubt. He who did not spare His own Son but gave Him up for us all — how will He not also with Him graciously give us all things? If God gave the greatest gift, will He hold back the smaller ones? Your daily needs, your future, your fears — they're all covered by the logic of the cross. The Father didn't hold back His Son. He won't hold back anything that's truly good for you.