One of the greatest challenges we face is the temptation to justify the means by the end. 
Often we have wonderful goals, however the process for achieving them is difficult since we have to do what is correct at every stage. Sometimes a few illegal and forbidden shortcuts would really help.  

This week's Parshoit (we read two this week) are all about how the Jews built the Temple as they were commanded. The only exception is the way they begin - with the prohibition of doing melacha (work) on Shabbat. This juxtaposition, explains the Talmud, tells us that even though the building of the Temple was so important, it could not be done on Shabbat. More than that, this is the very source of how we know what not to do on Shabbat. Only the 39 categories of creative acts which were used to construct the Temple are prohibited.

It's amazing to think about it - building the Temple is building a palace for the Divine Presence to rest in this world. There is no greater goal than this. However  when Friday evening comes, they had to lay down their tools and take a day's rest, thereby delaying this all important goal from being realized.
To teach us that the ends do not justify the means! We have to be clean and do the right thing at every stage.

Wishing you a wonderful Shabbos,