The United Methodist Church tells a story about John Wesley who one night had his "heart strangely warmed". It is a fine story and we use it as a proxy for talking about how religious practices that do not warm our heart are shallow. I cannot count how many times I have heard, "I just say the Lord's Prayer/creed/song, I just go through the motions." As though going through the motions is not only shallow but somehow a detrimental action toward spiritual formation.
Heschel is to Gandalf as Clark Kent is to Superman?
It is as though we only think something is worth doing if we really mean what we are doing. Put another way, we tend to believe the most valid expressions of religion/spirituality are those that have the proper motivations. We tend to think that only if your motivations are pure does the religious act have any weight. We tend to think that if we really do not "want" to be in worship or if we do not have the right motivations for being in worship then we should not attend worship. If we really do not mean what we say in a prayer then we should not say that prayer. Motivations are key in our popular understanding of religion and if our motivations are not in the right place then we are given a free pass to not participate in the religious act.
Abraham Joshua Heschel, argues that the way we get a pure motivation for a religious act is by practicing that religious act. He says "the way to pure intention is paved with good deeds."
The thing is we understand Heschel's thought when it comes to something like physical exercise. Even if you do not have the purest of motivations to get in shape or even if you don't believe in working out - just by running on a treadmill will change your body.
Or take reading. Even if you do not like to read, if you read everyday at some point you will be a person who reads. The more you read the more you are shaped as a "reader" and you begin to see a value in reading that you did not see as a "non-reader".
Going through the motions of a spiritual discipline is like learning to swim in the shallow waters. Over time, in the shallows, we become able to swim into deep waters.