Archbishop Justin Welby has told Christians firmly that we should not “proselytise” or talk about our faith to non-Christians until they invite us to do so.

It is a pity that St Paul didn’t have the benefit of the Archbishop’s guidance before he set out – without being asked – on his three missionary voyages in which he founded churches among the pagans in such as Philippi, Ephesus and Corinth. The presence of the finger-wagging, politically-correct Mr Welby on the quayside before St Paul boarded his ship would have saved the Apostle a great deal of trouble: the thirty-nine lashes he received (five times), an attempt to stone him and his shipwreck.

How ironic that Welby should choose the season of Pentecost to issue his injunction for, according to chapter two of The Acts of the Apostles, this was the day when the disciples of Jesus experienced the rushing mighty wind of the Holy Ghost and tongues of fire upon their heads and immediately rushed – all uninvited – out into the Jerusalem streets to preach to members of every race under the sun: Parthians, Medes, Elamites, dwellers in Mesopotamia, Cretes and Arabians and all the rest.

If only the wise, admonitory and well-mannered Mr Welby had been there to say, “Never mind the promptings of the Holy Ghost, St Peter! Mind your P’s and Q’s! Wait till you’re asked!”

And if we go back a little earlier to the life of Our Lord himself, we can imagine – if only Welby had been there to quieten Jesus’ enthusiasm – his command “Go ye therefore and teach all nations, baptising them in the name of the Father and of the Son and of the Holy Ghost” would never have been given. Or at the very least Jesus would surely have toned down his command to something more polite such as, “Go and ask those pagans if they’d like to join an Alpha course! Tell them there’s  red wine and pizza afterwards!”

Christian history would have turned out quite differently, if only Jesus had minded his manners.

But Welby’s verbal facility is not limited to the occasional sound-bite, such as “Don’t proselytise!” He is capable of quite extraordinary prolixity. How’s this for an example of what Humpty Dumpty called “Impenetrability”? In his Pentecost speech, he went on to say:

“I draw the line in terms of respect for the other; in starting by listening before you speak; in terms of love that is unconditional and not conditional to one iota, to one single element, on how the person responds to your own declaration of faith; and of not speaking about faith unless you are asked about faith.”

That is an utterance so syntactically obscure that Welby’s predecessor, the Great Obfuscator, Rowan Williams himself, would have been proud of it.