“Jewish messianic expectation is not in vain.”
“These Jews call the Christian faith into question; they do not accept that Jesus is their Messiah (Christ) and the Son of God. Christians cannot but contest the position of these Jews.”
Your quotes, from the same source, are quite contradictory.
This looks to me like the "Jewish messianic expectation" is actually referring to the attitude maintained before the coming of Christ, and the point is that Jesus is the fulfillment of that expectation. Hardly what you implied.