Spirituality describe the J Hudson Taylor's "faith principle" because he believes that nothing can satisfy the person will except having faith in Jesus and reading bible on daily basis can cause the true source of extraordinary power in the humans. However, he believed that transformation in the humans could be only possible through the spiritual principles which could promote holy living and uplift the world from human sufferings.
It is important to let others know about your accomplishments, however, you do not want to be looking for a reward in it. Also you don't want to seem like you want to be better than everyone else. Even if you are :) So agree!
I can only answer 3 i cant answer 4
