The Holy Saints John

In the Freemasonry blog, here:
All Blue Lodges are dedicated to these 2 saints. But we never hear any other information regarding these 2 important figures in Freemasonry or anything else to explain why they are so important to us as Freemasons.When a new candidate joins a Blue Lodge and is made an Entered Apprentice he is first introduced to and there is referance made to the Holy Saints John. They are referanced as the perfect paralles of Freemasonry as well as in Christianity. All of the other brethren are also reminded of these 2 saints. But who are they? Why are they so important to Freemasonry? Why are all Blue Lodges dedicated to them?....