Johan Cruyff painted the chapel; Barcelona coaches since merely restore or improve it," Pep Guardiola once said, long before he had sat in the Nou Camp dugout and carved out his own managerial legacy at the Catalan club.
Despite being the Catalan club's two most successful and influential coaches, these two kindred spirits met bitter ends. Cruyff was sacked after the trophies dried up and his relationship with president Josep Lluis Nunez grew ever more poisonous, while Guardiola called time by declaring: "Four years has felt like an eternity. I am empty and I need to replenish myself."
When the Manchester City manager returns to the Nou Camp for Wednesday's heavyweight clash against Barca he will do so with mixed emotions. He maintains a lofty place in the hearts of supporters who witnessed his evolution from ball boy to club captain and all-conquering coach. Fans and coach alike could not hold the tears back in his farewell game against Espanyol, when he finished an address in Catalan on the pitch by promising the Nou Camp faithful: "You will never lose me."
Yet he did not return to the stadium during his sabbatical between leaving Barca and starting work with Bayern Munich. He spent the year in New York, later saying "I went 6,000?km away to be left in peace".
The club hierarchy had always been suspicious of him for his close ties with former president Joan Laporta, who the new board took to court for mismanaging the club's finances. Even though Guardiola's arch-enemy Sandro Rosell has long left, his successor Josep Maria Bartomeu has not exactly extended a hand of peace.
In a recent interview with the Financial Times, Bartomeu doubted whether Guardiola could replicate the success he had at Barca with City. "Let's see if Pep can do in Manchester what he did for us," he said. "Pep came through our school." The Catalan media is not unanimous in its love for him, either. The editor of Mundo Deportivo, one of the two main sports newspapers in Barcelona and a big supporter of the current board, recently criticised Guardiola for signing Claudio Bravo from Barca for City. Sport, the city's other sports daily, remains a Guardiola disciple.
Guardiola did watch Barca play City in 2015, purring with delight when Lionel Messi nutmegged James Milner, but sat in his family's seat and not the presidential box.
There was no recognition from the club and no raucous homecoming either a month later when he stood in the visiting team's dugout for a Champions League semi-final with Bayern Munich.
That is partly because the club have moved on. In the four years since he left, they have collected 10 more trophies and are an even bigger beast commercially. They recently opened up an office in New York as part of their expansion plan, and last season posted record revenues of euros 679?million euros.
The team's style has evolved too, his obsession with control in midfield giving way to the hegemony of the world-beating trident of Lionel Messi, Luis Suarez and Neymar.
Guardiola's penchant for giving homegrown players a chance has also been lost. He gave 22 youth players their Barca debuts and turned Gerard Pique, Sergio Busquets and Pedro into club greats, but the only academy player to have made his mark under Luis Enrique is Sergi Roberto, who was given his debut by Guardiola.
Nonetheless, a core of players who so perfectly executed the coach's ideas on the pitch remain: Messi, Pique, Javier Mascherano, Busquets and Andres Iniesta. "I have kept everything I learned with him," says Messi, who tried to dissuade Guardiola from leaving in 2012 but confesses to not keeping in touch with the coach.
"He changed my career," says Mascherano. "I got to Barcelona at 26 and discovered there was another way to play football." Guardiola's closest relationship is with Iniesta. When the new coach was being questioned by the media after a winless start, it was the unassuming Spaniard who came knocking on his door to reassure him he had the backing of the players, insisting: "We're in f------ great shape".
Guardiola reciprocated that gesture a year later when Iniesta experienced difficulties with mental health, telling him to leave the training pitch whenever he felt uncomfortable. "He gives you so many answers, almost all of which are right," says Iniesta.
It is the devotion of the likes of Iniesta and Mascherano the supporters that Guardiola will remember back at the church of Barcelona. Yet, being the man he is, he will not forget how he was made to feel by the archbishops who remain in charge, who never showed him the gratitude he deserved.