Marriage is a real way to open up a miracle. Two strangers decide forge a life-long partnership in which they share every respect of their lives together under the same roof for 24 hours a day, seven days a week, 365 days a year for the rest of their lives, no other voluntarily made commitment is anywhere close to such magnitude.
Having seen and been through many “‘no’” signs, I can tell you that just getting to married is miraculous enough. Considering that we bring into this partnership our own individual backgrounds, values, perspectives, weaknesses, infirmities, personal history, minds, bodies, skills, imperfections, yearnings and disappointments, expectations fears, timidities, dreams and nightmares; all these are brought into a union to be forged together under the chuppah united into one permanent bond of commonality called marriage. It can only be a miracle that this mix actually works for millions of people, and is taken as our due. Whether we admit or acknowledge it or not, G-d is part of this relationship and natural and prudent that G-d be invited into the home created under the wedding canopy.
The Gemara asserts that creating a shidduch is as difficult as the splitting of the red sea, since this is acknowledged one of the most reported or important clear unexplainable miracles we’re aware of, there is no surprise that the answer to the question “How does G_d keep busy after the first week of creation?” is: “He started making shidduchim!”