This is probably a hyperbole that refers to being very careful. Alternate translation: "we must be very careful" (See: [[rc://en/ta/man/jit/figs-hyperbole]])
The peace and security provided by God are spoken of as if they were rest that he can give, and as if they were a place to which people could go. Alternate translation: "to enter the place of rest" or "to experience God's blessings of rest" (See: [[rc://en/ta/man/jit/figs-metaphor]])
God's promise is spoken of as if it were a place to which people were trying to go. Alternate translation: "none of you fail to enter into God's rest, which he promised to us" or "God allows you all to enter into his rest as he promised us" (See: [[rc://en/ta/man/jit/figs-metaphor]])