Following his decision to place the painting featuring a black Jesus above his altar, Dr John said: "The church is not in a strong position to preach to others about justice, racial or otherwise. But our faith teaches that we are all made equally in the image of God, and that God is of justice.
"Black lives matter, so this is why we have turned our Altar of the Persecuted into a space for reflection and prayer with this [the artwork] at the heart."
The 2009 painting, entitled "A Last Supper", is a rework of Leonardo Da Vinci's renowned 15th century mural and casts a Jamaican-born model, Tafari Hinds, as Jesus Christ.
The painting, by Lorna May Wadsworth, made headlines last year when it was discovered to have been shot with a pellet gun by a vandal whom she believed disagreed with her portrayal of Jesus.
Wadsworth said: "Painting the Last Supper altarpiece made me really think about how we are accustomed to seeing Jesus portrayed. Experts agree he would most likely have had Middle Eastern features, yet for centuries European artists have traditionally painted Christ in their own image.
"I cast Jamaican-born model Tafari Hinds as my Jesus to make people question the Western myth that he had fair hair and blue eyes. My portrayal of him is just as 'accurate' as the received idea that he looked like a Florentine.
"I also knew that, from a previous portrait of Tafari, there is something in his countenance that people find deeply empathetic and moving, which is the overriding quality I wanted my Christ to embody."
St Albans Cathedral, which dates back to the eighth century, is also covering its existing altarpiece painting with the high-resolution print.
