The phrase “there is God-shaped vacuum inside each of us” is attributed to 17th century philosopher Blaise Pascal. In my Internet research the other day, I discovered that Pascal never said those exact words. It’s what-we-call an “urban legend”—a myth or some misinformation that has been repeated so often and for so long, it is now considered to be true. What he really said is a bit more eloquent (if not also loquacious).
What else does this craving proclaim but that there was once in man a true happiness, of which all that now remains is the empty print and trace? This he tries in vain to fill with everything around him, though none can help, since this infinite abyss can be filled only with an infinite and immutable object, in other words, by God himself. -Pascal, "Pensees"
God designed us to have a relationship with Him: to belong, to love and be loved, to know we matter to Him. This means that deep within our being is a longing for God which will not go away. On some level, we are always conscious of our longing for God. But during times of stress, these longings increase, as does our need to satisfy them. Our attempts to fill the longings with anything other than God are like trying to fit a square peg into a round hole: the wrong shape—which, in this case, needs to be ‘God-shaped’ (whether Pascal used those words, or not!).