The present invention is directed to golf balls having a layer formed from a relatively soft HNP composition and a layer formed from a relatively hard HNP composition. Golf balls of the present invention have at least three layers, including an inner core layer, an outer core layer, a cover, and optionally an intermediate core layer. The present invention is not limited by which golf ball layers are formed from an HNP composition, so long as at least one layer is formed from a relatively soft HNP composition and at least one layer is formed from a relatively hard HNP composition. Relatively soft HNP compositions of the present invention comprise a highly neutralized acid copolymer preferably having a modulus of from 1,000 psi to 50,000 psi. Relatively hard HNP compositions of the present invention comprise a highly neutralized acid copolymer preferably having a modulus of from 25,000 psi to 150,000 psi.