David Steindl-Rast introduced me to gratitude as a sign that we are living in the present moment. He wrote, “Our eyes are opened to the surprise character of the world around us the moment we wake up from taking things for granted.” 
We have already noted that living here and now is an awakening. Through Brother David’s writing, I have learned it is the awakening of gratitude–what he names above as not taking things for granted. When we do not live in the present moment we miss a lot that is going on, and consequently we take those things for granted. When that becomes a pattern, we lose (or at least diminish) our capacity for gratitude.
The Bible exhorts us to give thanks. It is a way of pointing out things that are happening, and it is a sign that those things are being received by us. Gratitude is an outward witness flowing from an inward experience. 
Gratitude is an important way of remembering that we live in a grace-saturated world. Life is coming to us all the time. Gratitude is our response. Richard Rohr reminds us that our response to grace is not to earn God’s love, but rather to return it. 
Thich Nhat Hanh has added to my understanding of gratitude through his little books about walking, sitting, eating, etc. He says it simply, every act is “gratitude to all of life.”  And as we will gratefully, we also live joyfully.
Anne Lamott is bold to say that “thanks” is one of the three best prayers we ever pray. Prayers of gratefulness shape a pattern in us; they create a disposition of our hearts toward wonder, aliveness, surprise, hope, and love. Gratitude is an infilling with things that enliven us. 
 David Steindl-Rast, ‘Gratefulness, the Heart of Prayer’ (Paulist Press, 1984), 9.
 Diana Butler-Bass has written an excellent book, ‘Grateful: The Transforming Power of Giving Thanks’ (Harper One, 2018). Susan Muto’s book, ‘Gratefulness: The Habit of a Grace-filled Life’ (Ave Maria Press, 2018) is another one to note.
 Joelle Chase and Judy Traeger, eds., ‘Richard Rohr: Essential Teachings on Love’ (Orbis Books: 2018), 61.
 Thich Nhat Hanh, ‘Living Budda, Living Christ’ 10th Anniversary Edition (Riverhead Books, 2007), 26.
 Anne Lamott, ‘Help, Thanks, Wow: The Three Essential Prayers’ (Riverhead Books, 2012).