Could you tell me what preposition "in" or "to" should I use in the sentence below?
- I am passionate about making a positive difference in/to the lives of the children I visit.
I think of it this way
Having a boyfriend/girlfriend is a difference in one's life.
Winning the lottery is a difference to one's life.
A change in one's life can make a difference to one's life.
If you are trying to delineate that you want to make changes to those children, use "to", which indicates toward a subject.
If I am going to choose between in or to I would choose in. Also, I think into the lives of children I visit would work.