People have always been saved by faith.
No, but actually saved, not
by faith, but
through faith:
"For by grace you have been saved through faith. And this is not your own doing; it is the gift of God..." (Ephesians 2:8-9; emphasis mine)
"...He has caused us to be born again to a living hope through the resurrection of Jesus Christ from the dead, to an inheritance that is imperishable, undefiled, and unfading, kept in heaven for you, who by God’s power are being guarded through faith for a salvation ready to be revealed in the last time" (1 Peter 1:3-5; emphasis mine)
Our faith is not what saved (past tense) ~ or is saving (present tense) us. Otherwise, we should put our faith in our faith, which is a ridiculous notion and as such is quite the unsolvable conundrum.
Also, faith is not manufactured in oneself by... oneself. Faith is, as I'm sure you know, defined by the Bible itself as "...the assurance of things hoped for, the conviction of things not seen" (Hebrews 11:1). This assurance comes from God, and is a work in us of the Holy Spirit, a gift of the Spirit apportioned to each on of us per the will of God:
"Now there are varieties of gifts, but the same Spirit... it is the same God who empowers them all in everyone. To each is given the manifestation of the Spirit for the common good. For to one is given through the Spirit the utterance of wisdom, and to another the utterance of knowledge according to the same Spirit, to another faith by the same Spirit, to another gifts of healing by the one Spirit, to another the working of miracles, to another prophecy, to another the ability to distinguish between spirits, to another various kinds of tongues, to another the interpretation of tongues. All these are empowered by one and the same Spirit, Who apportions to each one individually as He wills" (1 Corinthians 12:4-11; emphasis mine)
Most Jews refused God, and God said he did everything he needed to do for them.
Sure. But God was not... flabbergasted... :)... or in any way surprised that they refused Him. Yet again, "not all who are descended from Israel belong to Israel" (Romans 9:6).
That does not address the issue of the fact that God wanted all Israel to be saved.
What God wants and what God purposes to do are two very different things. What God wants, or desires, He
may not purpose to do. But, some things He wants, He
does purpose to do, and
those things... always happen. :) When He wants them to. :)
That simply shows that it is only by obedience to the Gospel that either Jew or Gentile is saved.
Well, belief in the Gospel, and repentance (Mark 1:15). And ~ back to Ephesians 2, 1 Peter 1, and 1 Corinithians 12 above ~ that is a
result of faith having been given by God via His Holy Spirit. Obedience inevitably follows, and is a work of man
caused by God's working in us (Philippians 2:13).
Grace and peace to you both.