Approaching the Trinity from the point of view of human freedom is basically a matter of relevance.

If one imagines that the Trinity resides somewhere up there, high above the clouds, it will be seen as something remote and inscrutable, actually so remote and inscrutable as to become irrelevant.

If on the contrary, the divine mercy mystery is thought of as vitally connected with human freedom, it becomes the closest thing to us, and the most relevant.