There is a wealth of experimental data published on the change of molecular dynamics of epoxy resins during polymerization reaction. Common aspects are an increase of the primary alpha-relaxation time tau(alpha) and a broadening of the alpha-relaxation process during the polymerization reaction. In this paper we discuss systematic changes in the two secondary relaxations beta and gamma on the way from a neat molecular glass-former to the fully polymerized state based on literature data and new dielectric results for diglycidyl ether of bisphenol A (DGEBA) cured with ethylenediamine (EDA). The discussion is focused on common trends in the relaxation time tau(beta) which were not reported previously. It is shown that the relative changes of tau(alpha) and tau(beta) during the polymerization process are in accord with the predictions of the coupling model and that it is the beta-relaxation which is the initiator of the alpha-relaxation of the epoxy resins in its neat state as well as the initiator of the local segmental relaxation of polymerized or cross-linked epoxy resins. In the terminology of small molecular glass-forming substances, the alpha-relaxation of the epoxy resins would be called the Johari-Goldstein process.