Offgrid, you delved into history, a subject I love, to share this interesting point of view. It sparks a good conversation. This man Spinoza sounds extremely intelligent, and he very well may be on certain topics, but by his own words he confesses some ignorance on the topic of the incarnation of Jesus Christ (that is, knowing Him according to the flesh) and he exhibits it as well. The New Testament itself states that Jesus Christ (Yeshua the Messiah) did come according to the flesh in countless verses. Here's just a few of them, off the top of my head...

--John 1:14 The Word (the Divine Logos) became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth.

--The genealogy of Jesus as recorded in Matthew and Luke is written so that we would know that although He had no earthly father, He did have an earthly mother (and was adopted in a sense by Joseph)

--but made Himself of no reputation, and took upon Him the form of a servant, and was made in the likeness of men.(Philipians 2:7)

--and every spirit that does not confess that Jesus Christ has come in the flesh is not of God. (I John 4:13)

Jesus is 100% God and 100% man. Not half and half. Some deny one or the other, or both, and it is equally bad to deny either.

Jesus said this--harsh words, but He said it, originally in context to the Jewish leaders who refused to believe He was the Son of God, but it applies to us today as well: "That is why I said that you will die in your sins; for unless you believe that I am who I claim to be, you will die in your sins.” (John 8:24)

But to leave off on a more optimistic note, Jesus also said, "For God did not send his Son into the world to condemn the world, but to save the world through him." (John 3:17) So if we recognize our sin, our need for a savior, and believe Jesus is who He claimed to be, putting our trust in Him for salvation, we will be saved. And that is what God wants!