Do you classify Sikhism as a religion or a way of life? When people argue (particularly Muslims) by saying that Guru Nanak did not create a new religion? Can we not say, Yes, you are right. Sikhism does not adhere to any "rights and wrongs" but is a path, a way of life to be followed that was proven by the actions of the Gurus to be correct. Guru Nanak said himself Sikhi has long existed before him, and will exist past him. Sikhism can be seen as a foundation for base, a "free-thinkers" world, where the foundation is created by reading Sikhi, to create a philosopher who then thinks on his own without boundaries. Many religions have a "cap" where they have certain answers for questionable things and if you do not believe those answers, then you can not be part of that religion. Sikhism has no such thing, it creates a base of knowledge, so you can keep pondering those questions and search for the truth in your own manner. The Khalsa was the brotherhood dedicated to purity of thought and action. The formal union, making the complete Sikh, on what it should be.