A man's ethical behaviour should be based effectually on sympathy, education, and social ties and needs; no religious basis is necessary. Man would indeed be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.
How important the concept of God is, and how instead of valuing what has been given us, we with light hearts spurn it because of absurdities that have been attached to it.
Our self (Soul) is maya (an illusion) where it is merely individual and finite, where it considers its separateness as absolute; it is satyam (truth) where it recognizes its essence in the universal and infinite, in the Supreme Self, in paramatman (God). This is what Christ means when he says, "Before Abraham was, I am" (i.e. before Abraham was God, who is the same that is in my soul - I am That.)
If something is in me which can be called religious then it is the unbounded admiration for the structure of the world so far as our science can reveal it.
The universe is large and we are tiny, without the need for further religious superstructure. One can have so-called spiritual moments without belief in the spirit.
Its unadulterated belief in the oneness of God and a practical application of the truth of the brotherhood of man for those who are nominally within its fold are two distinctive contributions of Islam.