We recognize the multitude of tests, temptations, and tribulations that could pull us away from all that is virtuous and praiseworthy before God. But our mortal experiences offer us the opportunity to choose holiness. Most often it is the sacrifices we make to keep our covenants that sanctify us and make us holy.
Carol F. McConkie, "The Beauty of Holiness", General Conference, April 2017
If you look up "holiness" in the Bible Dictionary, you read...."things or places were holy that were set apart for a sacred purpose".
We are set apart for specific callings, like to be a missionary, right? And in order to be a successful missionary, one needs to follow the rules and work hard.
So, can we summize that we are "set apart", not just commanded, to live a higher law as members of the church? What exactly does "set apart" mean? It means, that as long as we live according to God's law, we will have everything we need to move the work of the Lord forward according to His will. Everything we need. We are promised that.
We are set apart to be holy!
We are commanded to walk "in holiness before the Lord" (D&C 20:69) and we are set apart to do so. Not just willpower, or the strength of our desire, but because, by power of the Priesthood, we are entitled to everything we need in order to do so. Think about that. Legions of angels, if necessary, are a possibility to help and keep us holy.
We are also commanded as disciples to "stand in holy places" (D&C 45:32). That, of course, is the temple, church buildings, and even our own homes. How better to become holier when standing in a holy place? Our homes must be a holy place to stand in.