There are a number of things that I thought about when reading today's passage. In fact, I wrote about one of the things three years ago on this day. You can read that post HERE.
There is something lost in Christianity today in that we somehow miss God's holiness. I love how God gently reminds Moses of this important character trait of His by asking Moses to remove his shoes as a symbol of submission to God's holiness. Often today we like to talk about being God's friend and of having an almost casual relationship with God. Whereas Jesus did teach us about having an intimate relationship with our heavenly Father, I'm not so sure that such a relationship should seek to nullify God's holiness the way it has done in our culture.
God is still holy, and He asked Moses to remove his shoes in His presence. We would be wise to approach God with a similar reverence. After all, God does not change – He is the same yesterday, today, and forever. That's why He told Moses to say "I Am" sent him. "I Am" is present tense; never past. God dwells outside of time in His holiness.