"The Lord also said to Moses, 2 “Give the following instructions to the entire community of Israel. You must be holy because I, the Lord your God, am holy." Lev 19:1-2
If a man had said this, it would have been arrogant and less than compassionate. If we see God as just like one of us, it can feel that way coming from Him too. When you look at the rules he lays down in these two chapters, you get an entirely different picture.
The sexual immorality depicted in Lev. 18 is the reason why the land is vomiting out the people from the place they're about to go. Besides, there's all kinds of implications for the redneck stupidity listed in that chapter--implications for which they have examples. Is it a good thing to marry both sisters? Jacob didn't fare too well with it. Your family tree should have forks.
The stuff in Chapter 19 seems pretty obvious to us, with few exceptions, but no one had ever said these things before. Most of these are just a matter of treating each other with kindness and compassion.
God's instructions to us are for our good. His encouragement to be Holy like He is Holy is for our good, because doing otherwise will get us or someone else hurt. He knows His lifestyle is best, not for Him--He doesn't need anything. It's best for us. We are fragile and need to treat ourselves and each other gently.
Even the regulations for the day of atonement and for sacrificing only at the front of the tabernacle are intended to protect His people. After the problem with Aaron's sons, God made the rules for atonement more explicit and even required that all others be outside of the tabernacle when the High Priest went in to make atonement. And to keep the community from idolotry, all sacrifices were required to be performed at the entrance to the Tabernacle. That way if they were doing something wrong that might offend God, they could be taught how to do it well.
Jesus ultimately gives the same instructions and again, it is for our good and His glory--both things we want.
Be holy...It's good for you.