The following verses from the Ofudesaki succinctly address spiritual growth.
There are a great number of people living throughout the world, but their minds are all as if in a haze.
Day by day, your innermost heart will be purified and understanding will come. You will come to see the truth as you mature.
The phrase “as you mature” refers to spiritual growth which allows the “innermost heart” to become “purified” and enables “understanding” to emerge. These verses say that one will come to see God’s workings as the mind matures day by day. If one is to perceive God’s intention (intent and plan), the effort need be made to allow the mind to clearly see the unfolding of things in a wider and deeper context rather than be captivated by the world of phenomena.
Says The Doctrine of Tenrikyo:
When the mind of tanno [joyous acceptance] is settled and the body is spirited through efforts of hinokishin in which greed is forgotten, there will emerge the virtue of true sincerity, a virtue which is most acceptable to God the Parent. Then our lives will overflow with clearness and brightness. We shall be able to perceive the intent of God the Parent without error and respond in exact manner. When we have attained true sincerity, our spiritual growth will have been completed. This is the state for which God the Parent longs.