If you do a Google search on God-shaped hole, you come up with many explanations about the origin of the term; from a quote from a book by Blaise Paschal to St. Augustine's famous "our hearts are restless, O Lord, until they rest in you."
I have been contemplating this empty space in us that only God can fill, and I come up with my own explanation.
If you look in a full-length mirror you can see how large the space that God longs to fill is. It is our whole being.
He longs to fill our mind with His word; Sacred Scripture. He wants us to learn about Him and His ways so that we will follow them.
He longs for our eyes to look upon His creation both in nature and in each other and be in awe, so much so that we refuse to look upon things that are abhorrent to Him so as not to offend Him.
He wants our mouth to be full of Him; praying without ceasing, singing His praises, bringing Him to others whom we meet by a kind word or an "I'll pray for you."
He wants our ears to hear only that which is life-giving and affirming. We don't need to be a part of gossip or trash talk.
He wants our heart to be full of love for Him and to long for heaven and union with the Beloved.
Our hands are to be His hands on earth. We can find a thousand ways to serve Him if we only look for ways to incorporate the corporal works of mercy into each day.
Our arms are His arms for hugging a crying child or a friend in need.
Our feet are His feet. They take us to His Church for Mass, to hospitals and nursing homes to care for those who are lonely and ill. They take us to soup kitchens were our help is needed to serve the homeless and hungry.
Our whole being cries out for God to fill us with Him so that we can be His light in the darkness of the world.
Dear Lord Jesus, fill me with You! Let all who encounter me know that you are the center of my life. Amen.