I said in an older post that God always gets His way. I was thinking of other examples of this, such as Mordecai telling Esther "if you remain silent now, then relief and deliverance will come to the Jews from another place" (Esther 4:14). Esther could have said no, and God would have provided deliverance through someone else (but Esther would have died). None of us are indispensable to God's plan. But that was not the case with Jesus. If Jesus said "no" to His Father, then deliverance would not have come. There would have been nobody else to provide us salvation. We all would have been lost.