When Latimer was committed to the Tower on 13 September 1553, Bernher attended him there, and the next year waited on him and the other bishops imprisoned at Oxford.
Throughout the Marian persecutions he was a constant friend to Catholic martyrs, and a kind of overseer to the wives and fatherless children of those who died for their religion.
In a letter written shortly before his death, Robert Glover bade his wife be guided by Bernher, whom he called "an angel of God"; and John Bradford, writing from his prison, addressed him as "my own good Augustine".
He comforted and attended on Glover, Careless, Joyce Lewis, and Cuthbert Sympson, who suffered martyrdom in 1555–8.
He wrote Testimonies taken out of God's Word, &c., An Answer to Certain Scriptures, &c., manuscripts in the Bodleian Library, Epistola ad dominum suum (Ridley), a manuscript in Emmanuel College, Cambridge, and edited Latimer's Sermons with a Latin preface addressed to Catherine, Duchess of Suffolk, (published 1572, another edition 1635), and Latimer's Works (Parker Soc.