Read 1 Peter 2:4-12."...you also, like living stones, are being built into a spiritual house to be a holy priesthood, offering sacrifices that are acceptable to God through Jesus Christ." NIV
Peter has been telling us that we have received God's mercy through Jesus Christ and will receive our inheritance. Now, we need to prepare our minds for action and as purified followers, love one another deeply from the heart. As strangers in this world, we do not conform to its ways, but put off malice, envy, deceit, hypocrisy, etc. All of these actions lead us up to the fact that we are being transformed into a spiritual house for our Lord. He resides in us and we must surrender our "home" to Him as a holy residence. My acceptable sacrifice, therefore, is allowing Him full reign and use of my being. I may be dealing with the Almighty Creator of the Universe here, but He is a gentleman and will not overstep the bounds of free will. So it's my job to, through His power, overcome the enemy that battles for my soul and allow God to use me in any way He chooses. I do so not out of the law, but out of love for my Lord and Savior. I am in relationship with the Almighty and choose to do nothing less than serve Him with my entire being.
That idea and all it encompasses is overwhelming to me, yet at the same time very simple. Consider the vastness of the universe; God spoke it into existence. Then realize that He wants to use you for His honor and glory. That is so humbling. Who am I? The answer is "No one." But I was chosen by huge God who is the I AM. And that's all I need to know.