 While the Yevon church forbids most machina including weapons , it retains machina weapons to ensure its dominance . The Al Bhed are seen as dangerous to the Yevon clergy because they use machina and pose a threat to the church 's uncontested control of Spira . The church retains its power by role in using the Final Summoning which results in the sacrifice of the summoner and her guardian to prevent its secrets from being divulged . Though Yevon set up Operation Mi ’ <unk> to instill further loyalty to the teachings by making the Crusaders use machina that would never win against Sin . By the end of Final Fantasy X , the Yevon religion was effectively disbanded once evidence of its corruption was discovered , and its remaining priests volunteered the truth . Half a year later , the moral teachings of Yevon were revitalized in the form of the New Yevon Party , later led in Final Fantasy X @-@ 2 by Praetor Baralai . Although technically a splinter group of Yevon , the New Yevon party was not a religion , but a simple philosophy , their motto and position on Spira 's advancement being " One thing at a time . " 
