Theoretical teachings are certainly very important, since they point to the goal and give clear view on the things. If a Buddhist view is close to a person, then Dharma text inspire, bring to contemplation and awaken inner wisdom. However just words, even very wise words, would not be enough: once they will be forgotten. As Indian Yogi of X century Tilopa said: “Theory is a patch, it will become worn out and fall off”.
It’s not possible to be a Buddhist while sharing only the view without applying the methods. Knowledge for the sake of knowledge is meaningless: one only needs it to support practice, which changes a person. Buddhist doesn’t “confess” Buddhism but practices it. Meditation, or formal practice, is the exercise for the mind (sometimes body and speech as well) used to achieve a definite spiritual goal.
However it’s not enough to just know the theory and meditate: meditation for the sake of meditation is meaningless. Its purpose is to help a person to live better, die better and get reborn better. Therefore we also need particular instructions for behavior in everyday life. Those can be called informal practice. Life is full of surprises: we occasionally face some unexpected obstacles, we lose some things; the circumstances don’t always shape up the way we want. People experience a lot of influences, interact with each other, carry responsibility for themselves, fulfill some obligations in the society etc. Along this one needs to stay compassionate and attentive to keep the balance, be joyful when possible and useful for others.