A friend of mine shared the essay "Reclaiming Awe: An Advent Prayer Experiment with My Students" with me a few weeks ago, and I've thought about it a lot since I read it. An excerpt:

Feeling completely at ease with God is not wrong so much as it is imbalanced. In constantly relating to God as my heavenly Father and friend, I have slowly lost my sense of awe. Over time, I’ve stripped God of attributes that make me feel uncomfortable—holiness, sovereignty, omniscience—and fixated on the ones I take comfort in—kindness, trustworthiness, love, and patience. God has become a glorified version of the best of human characteristics: a God who is reliable but not majestic; a God who is reassuring yet not fear inducing. My lack of awe is most evident in my prayer life. Over the years, I’ve adopted a casual approach to prayer where I primarily communicate with God while doing other things—walking the dog, driving to work, or sitting in my favorite chair sipping coffee. In short, most of my prayers are distracted and lacking any sense of the divine.