And why not? Because it was not by faith [that they pursued it], but as though it were by works [relying on the merit of their works instead of their faith]. They stumbled over the stumbling Stone [Jesus Christ].

“Then He shall be a sanctuary [a sacred, indestructible shelter for those who fear and trust Him];
But to both the houses of Israel [both the northern and southern kingdoms—Israel and Judah, He will be] a stone on which to stumble and a rock on which to trip,
A trap and a snare for the inhabitants of Jerusalem.

and,“A stone of stumbling and a rock of offense”; for they stumble because they disobey the word [of God], and to this they [who reject Him as Savior] were also appointed.