Motivated by the observation made by R. H. Dicke in 1957 that the speed of light seems to be correlated with the gravitational potential of the entire universe, we suggest a modification of general relativity to incorporate a wavelike gravitational potential. We show that the gravitational force derived from such a potential is an emergent property of matter and critically dependent on the distribution of mass on both local and global scales throughout the universe. The theory is free of gravitational singularities. It provides a path to numerically computing the critical acceleration in modified Newtonian dynamics theory (MOND), providing an alternative explanation for dark matter. Finally, we develop a cosmological model and fit the model to high-redshift supernova data from the Supernova Cosmology Project, showing that we obtain an excellent fit with only baryonic matter.