https://www.themindfulchristian.com/renewal-of-the-mind–neuroplasticity.html

On a spiritual level, our tendency to mentally wander through the past and imagined future creates distance between ourselves and God. Because we can only be in the present moment, we can only meet God in the present moment. When we don’t show up for the moment, we are unlikely to notice God with us. This is particularly true because God tends to speak in the quiet of the heart. A lot of mental noise about things past or future can easily crowd out God’s “still small voice” in the moment. This explains why God is so explicit with his repeated command of “do not worry” (see Philippians 4:6 and Matthew 6:34 for examples).