The Trinity can be illustrated by some of the TV commercials for Progressive Insurance -
the ones where several roles are shown on screen,
all at the same time, all portrayed by the same actress.
The Trinity is similar. The Trinity is one person appearing in multiple roles, all at the same time.
Each role performs its function. The one person is performing all of the functions.
No, actually that view of the Trinity was condemned as heresy by the ancient and undivided Church (look at the entry for Sabellianism in
The I Spy Book of Heresies we Orthodox Christians are issued).
Now, that was an actual joke -- there is no such book, but we Orthodox are very good at recognizing ancient heresies in new garb, so some wag once suggested we had such a book.
One of the fundamental principles of traditional Christian theology is that there is no likeness between the created and the Uncreated, and that God transcends all created binary distinctions (as for instance the distinction between unity and multiplicity).