What are the origins of the 15 steps at the Seder on Pesach?

Question

the 15 steps jews go through (kadesh, urchatz, karpas...) and so on, are all there, my question is where did they come from and why do we say them (aside from the drinking 4 cups of wine, that fine with me) any answers, your own or from websites, would be much apreciated, thanks for your time!

Answer 1

The Sages say that Passover occurs on the 15th of Nissan (the Jewish month), to teach us that just as the moon waxes for 15 days, so too our growth must be in 15 gradual steps. Think of them as 15 pieces of the Passover puzzle.

Answer 2

I have to agree with the Aish website on this one, so the link of the first answer is good..