This is something I don't get. In FFX's time, summoners must use the Yevon rites to acquire an aeon. Since this was done through Yevon rites, how did they summon way back 1000 years ago? The only thing I can figure is that they didn't need fayth to summon in the long ago Zanarkand.

Well Yuna didn't need Yevons rights to obtain the final aeon. She didn't recieve it but she could have if she did't kill Yunalesca.

However, the Yevon rites imprisoned souls in statues. It's pretty much the same thing. She would have had to sacrifice the life of one of her Guardians to summon her Final Aeon.

Not really because they would have never given her the opportunity to get the final aeon if it meant using some of Yevon's teachings.

They needed fayth to summon 1000 years ago. It has nothing to do with Yevon. Yevon just makes it "officially recognized."

Imagine being trapped in a statue until some twat with a big stick went on a pilgrimage and prayed for you to come out of the statue

wasn't Yevon around in zanarkand back then? cuz he made sin.......

to summon, you need fayth.and, in zanarkand a thousand years ago, the people sacrificed themselves to become fayth in order to let people summon so that they could defeat...bevelle, was it? this is just like what (WARNING!!!!SPOILER AHEAD!!!!!! DO NOT READ IF YOU HAVE NOT FINISHED THE GAME!!!!!!)) seymour's mom did in order to let him summon anima.seymour's mom is the fayth of anima.

to summon, you need fayth.and, in zanarkand a thousand years ago, the people sacrificed themselves to become fayth in order to let people summon so that they could defeat...bevelle, was it? this is just like what (WARNING!!!!SPOILER AHEAD!!!!!! DO NOT READ IF YOU HAVE NOT FINISHED THE GAME!!!!!!)) seymour's mom did in order to let him summon anima.seymour's mom is the fayth of anima.

not really 1000 years ago zanarkand and bevelle was at war and zanarkand did not stand a chance so the summoners and the people of zanerkand that was left came together and sacrificed them self to summon the dream zanarkand there was no aeons that time and bevelle had there macina like missiles and guns and sit and that was a thousand years ago that does not mean bevelle did not have summoners.
and thats where yu yevon comes along, a sommoner from spira he just wanted to summon, thats all he wanted to do, but he had to protect himself
so he summond a big ugly 100 eyes bird fish called sin to be his armur and so he summon's from inside sin so thats that.

now we have a big problem sin is killing people and we have to kill it
ok we bevelle will take some people's souls and make them aeons
and poeple with the ability can become summoners that summoner will train
to be the strongest then you will get to the final aeon and that one will be the strongest aeon that will kill sin YES YES I DID IT GOT FINAL AEON
I'M GOING TO KILL SIN?YES YES YES I KILLED SIN O MY GOD I KILLED SIN
WHO'S YOUR KILLER WHO' YOUR KILLER!!!........OOPS NO NO IT CANT BE IT CANT BE? YU YEVON JUMPED INTO FINAL AEON AND KILLS THE SUMMONER AND YU YEVON TAKES TEN YEARS TO SUMMON THE FINAL AEON INTO SIN AND SO THE SPIRAL GOES ON AND ON.
SORRY FOR SPELLING
THANK YOU FANS THAT WAS FUN SIN YOU NEXT TIME

SPOILER (and my view of things)! DO NOT READ IF YOU HAVENT FINISHED THE GAME!!! Yevon was once a summoner from the old 1000-years-ago Zanarkand. When Bevelle finally attacked Zanarkand, he knew that their Machina would be too strong to withstand them. So, in a great and terrible summoning, he forged a weapon, an armour, that we now know as SIN. with this armour, he (eventually, nothing completely clear ist said about this) destroyed Zanarkand, in order to not let it fall into Bevelle's hands or be destroyed by them. Then he crushed the forces of Bevelle (or threatened them to retreat) an began to prey for all the Machina he could find all over Spira, in order to not let them emerge and be used and bring the destruction to Spira again, as they did in times of thatr war. From that time on, he was called Ju-Yevon ("ju" is the Japanese word for "bain" or "curse". I know, in the game it says "Yu", but that is simply a mistake in the english translation or spelling)

So this has nothing to do with any rites of the order of Yevon, it is just necessary if you want to be able to summon...
And in my oppinion all summoners (even those back 1000 years ago) need fayh to summon, so there have always been fayth and people who sacrificed themselves in order to become fayth to lend their power to summoners in the shape of Aeons.
perhaps they were individuals with great magical or physical powers, so they were really sure about what they were doing and knew, that it would be for a good purpose, for the higher good, if the sacrificed their bodies, only to offer their powers to someone able to wield them - and so they did over centuries, as we know. I don't wanna estimate how old Bahamut or Shiva may be... Eventually there are even more temples and statues of the fayth hidden or sunken all over Spira... Perhaps there are Aeons that we will never even hear of...

Even now some do still know how to perform this kind of sacrifice, as we can see at the example of Seymour's mother. Who knows who ever could have done this for their child, as well? ;-)