Mitvah -In the time of Moshiach

Hashem wanted to make us righteous therefore he gave us an abundance of torah and mitzvos, to keep us busy from morning to night. Righteousness is a by-product of the mitzvos we do because we have freedom of choice. When we chose to do the right thing we are able to be righteous.
Freedom of choice is a necessary requisite for the concept of a mitzva being fulfilled.
Will we have the ability to make a choice when moshiach comes?
When moshiach comes there will be no challenges, there will be no difficulties, and we will not have the opportunity to make a choice. We will not have the ability or the challenge to decide to do the mitzvah or not to.
We will all be doing exactly what we are supposed to do, we will all be in perfect sync with Hashem's Will, doing the mitzvos, almost robotic. But with that of course comes the loss of thrill when we DO overcome a challenge.
That thrill and accomplishment can only be achieved NOW, in galus.
Not only is it a physical thrill and joy, but a spiritual reward as well, which we will merit to collect when Moshiach comes. The more difficult it is to do the Mitzva now the greater the reward will be then. More of G-dliness will be revealed.
That is why we need to utilize every moment NOW - till moshiach comes - to gather and to collect as many mitzvohs as possible -
For once Moshiach comes the opportunities of galus will be gone.