Why does God ask us to sacrifice all things? Why is it that those who do not or are not willing to sacrifice all things cannot gain the same reward as those who are willing? Does God get something out of this? Does it benefit Him in any way? Or is it helping us let go of the things of the world? Is it helping us to focus on the things of the Spirit? Is it to help us stop fearing that something of ours (life, belongings, family, prestige, power, money, friends) will be stolen or lost?
In my mind it is similar to the post I just wrote. There is a purpose, and that purpose is to benefit God. To teach us. To help us become like our Father in heaven.