parshat Tetzave

Ever since the dawn of time, people have pursued the goal of eternal life. The ancient Egyptians, for example, mummified their bodies, in the belief that this would grant them continuity from one world to another. Even today, many contribute to various Torah or kindness organizations in order to memorialize their loved ones... On a simple level, the aspiration for eternity stems from a positive place in one's soul: the striving to be like our eternal Creator. If so, when we consider the other levels of G-d's creation, we will realize that we are not very close to reaching this goal...

Why aren't the Muslims and the Christians able to build the temple even though they've been trying for hundreds of years? What are they missing out?