The subjects are connected with the Passover: the Lamb in the centre panel, the Destroying Angel in each side panel. A gilded cross in the ceiling is above the site of the original altar. The pilasters to the reredos are carved with arabesques symbolical of the Resurrection. The new decorations, full of symbolic references and scriptural quotations, with Alleluia as the central theme, were in the neo-classical style combined with the pre-Raphaelite love of detail.

Behind the altar table hung an oil painting of the Holy Family, painted by the American-born artist Benjamin West, who had lived in Marylebone for many years. His dedication can be read – with difficulty – at the bottom right of the picture. Above this picture was the organ console and case. On the night of 31 March 1859 the painting was scraped with a knife and some tablets were also defaced. It was found to be the work of one John Hughes, who had been confined to Hanwell Asylum. The painting was restored by the Courtauld Institute. Paintings (now covered) between the windows represent Death, Life, Noah, St John the Baptist, David, Virgin and Child, Isaiah, The Captain of Our Salvation, and Justice, plus a medallion head of Malachi, a figure of Mercy and a medallion of St John the Divine.

The church suffered damage in World War II and remained closed until 1949. Pieces of iron railing from the school playground perforated the ceiling over the reredos in two places when a bomb fell in the churchyard close by, and the windows of the apse were destroyed.