This paper aims to present the main challenges of collective identity-formation including theoretical and practical aspects. The author builds on the constructivist and functionalist theoretical model of identity-net when explaining the dilemmas of the common identity. The following questions are raised in the paper: Is the civic component of European identity fading away? Do EU citizens trust their European and national institutions? What is the effect of refugee crisis on the identities of EU citizens? In what way the spread of differentiated integration does re-shape collective identities? Who are “the others” for EU citizens inside and outside the EU? Are there any commonalities and differences between member-states with regard to identity formation patterns? In order to be able to answer these questions, an interdisciplinary approach is taken. The arguments presented in the paper are supported by the data of the recent opinion poll surveys.