There is no true identity for man without religion. Actually, what is identity? All the things humans attach themselves to such as nation, country or tribe etc.., are all superficial. True identity lies in the deep connections and attachments. We all know that those attachments are shallow and there is a deeper one. We know that the nation or family name doesn't change much. If we were in a different country we would still be us, and if our name or family name is different nothing real has changed. A person his name is John for example, can't he be Richard, George or Omar? It's only a change of letters and their arrangement. Those are the information in your Identity Card. Nothing in your ID card can determine your identity more than religion, because it is a connection with the deep and constant, at least you view it this way.      

Thus, lack of religion makes a person lacks true identity, except those attachments which aren't deep and not specific to the individual himself, (you know things from their relationship with yourself, and you know yourself from your relationship with God).

That's why who strictly adhere to those shallow attachments is called a fanatic. Extreme attachment to a nation is called chauvinism or Nazism, extreme loyalty to skin color and race is called racism, and extreme attachment to a certain sect is called sectarianism. All those images are ugly and despised, and all can be destroyed by logic and doesn't stand up for criticism. There is no real difference between being an Asian, European or African, being black or white, and being German, French, Indian or Chinese.    

What is the difference that can really differentiate? Nothing can clearly differentiate more than religion. The choice between good and evil is the clear difference, this choice is the true identity. Who has lost his religion has lost his identity. There is no real value for the ID card except where it's needed, it's more valuable to the government employee than it is for its owner.

One of the signs of the superficiality of the common identity attachments is that they attach to the close blood relationship, the new nation or new home country. There is no value for the old home or the old blood relationship, this is a proof of superficiality.  

Atheism is a true lie. Even the atheist deep down is attached to his old religion. Israel is an evidence for that, it's a secular government and many of its leaders are atheists, and yet they came to serve what they call a national project, while it's a religious one.

Immanuel Kant assures that identity is built on the basis of our relationship with others. But he didn't clarify its mechanism. Religion, however, organizes one's relationship with others, which means that religion is the basis of identity not others.  

Identity is the answer to the deep question: who am I and why do I exist? When one says: I'm a slave to God for the rest of my life, here identity is accomplished. True identity is found in slavery to God, it can't be changed by the change of one's home country or any other attachment, because it's deeper than all of them. One's home might change, so is one's language and customs, but religion doesn't change except by free choice. All the other information required for identity are unnecessary, thus identity is reached when slavery to God is reached, {I created the jinn and humankind only that they might worship Me} the Quran. All other identities had been acquired through culture, and true identity is discovered by an internal motivation and from what one has consciously chose from his/her religion, not from all one knew about religion without choice. True identity isn't reached by an outer pressure or an external motivation, the person has searched and found that s/he is a slave to God. Here one has stopped and became a person with identity.