It would be premature as well as irreverent to invoke the eviction of money changers from the Temple But to judge by yesterday’s showing, bankers would be highly unwise to mess with His Grace.

Having decided to remain on the Parliamentary Commission on Banking Standards despite being named as the next Archbishop of Canterbury, Bishop Welby not only turned up at yesterday’s session. He made a difference.

You couldn’t help wonder if the financiers might have preferred him to confine himself to his enlarged pastoral duties. It’s not just that his theological dissertation was ominously entitled “Can business sin?” Or that he recently told a conference that before 2008 “the industry was referred to as financial services, but in fact it served nothing”.

Or that having worked in the oil business he knows what high finance is all about. As a man who by all accounts repeatedly risked his life negotiating with –and at times being kidnapped by– fearsome warlords in Nigeria, he is unlikely to be intimidated by men in pinstripe suits, however expensive.

Whether or not in deference to his new job, he was yesterday promoted to a seat between former Chancellor Lord Lawson and the Commission’s chairman Andrew Tyrie who simply referred to him – so grand is this august and erudite body – as “Justin Welby”, despite his cross, the unobtrusive dog collar and the imposing nameplate proclaiming him “The Lord Bishop of Durham”.

His Lordship is the polar opposite of Gerald Ford who, according to LBJ, couldn’t walk and chew gum at the same time. Indeed he is such a multi-tasker that he managed to tap regularly on his iPad, write – with pen and paper – copious notes and ask some of the more intelligible questions of yesterday’s witness, Sir John Vickers, the man appointed after the crash to recommend reforms of the stricken banking industry.

Asking about “cultural contamination” across the “ring fence” that Vickers proposed will henceforth separate the investment and retail arms of banks, he suggested that an investor-banker chairman would be able to influence the retail side of the business, not by “subtle osmosis” but by simply declaring “we’ve got to push these dozy people in retail to be more aggressive”.

He gave a dry and pregnant laugh when a heavily sceptical Tyrie asked whether Vickers’ view that bank directors would be entrusted with enforcing the “spirit as well as the letter” of new regulations, meant that “we have got to rely on bankers to deliver this [because]…their hearts are in it.”

And the Bishop asked Sir John, with just the faintest hint of incredulous distaste, whether it would still be possible for a bank’s retail operation to sell derivatives “manufactured” –the term used by his Liberal Democrat fellow Commissioner John Thurso – by the investment arm.