The teaching set forth in Matthew chapters 24 and 25 is commonly identified as the Olivet Discourse and contains a detailed explanation of the end-times.
A man or woman who took the vow of the Nazarite, did so of their own free will. It was a person from the depths of their heart wanting to separate from the world and unto God. Do you love God enough to separate yourself unto Him?
If God would break His promises to Israel, He might break other promises. But He never does. What other promises can we rest assured that He will keep?