Humans are social creatures that interact in a number of different and at least partially independent social settings, such as work, home, social and political organisations, and church. In each setting one has an identity, or set of identities, which one is called upon to achieve. To obtain and maintain an identity one must dedicate scarce resources. The benefits of expending these resources may be, among other things, income; wealth; success; prestige; power; security; respect; social acceptance; spiritual fulfillment; and salvation. To better understand how the individual makes his resource allocation decisions given the many possible interactions, both positive and negative, across his identities, changes in collective beliefs defining identity, and the substitutability or complementarity of identities, we develop a simple behavioural model of an individual whose personal identity is an amalgam of two identities. We interpret the model in the context of an individual with a secular and a religious identity.