He was educated at Oxford and entered the service of Queen Catherine as her chaplain some time before 1528 and appears to have taught the queen modern languages and music. Catherine sent him to Spain in 1528 to the emperor Charles V on a mission relating to the proposed divorce. On his return she presented him with the parochial benefice of Bradwell, in Sussex, and remained to the last a staunch supporter of the unfortunate queen in the case of the validity of her marriage with Henry VIII.
In 1532, he published his Invicta veritas. An answere, That by no maner of lawe, it maye be lawfull for the moste noble Kinge of englande, Kinge Henry the ayght to be divorsid fro[m] the quenes grace, his lawful and very wyfe. B.L.. Abel's treatise was printed by Merten de Keyser in Antwerp with the fictitious pressmark of Luneberge, to avoid suspicion. The work contained an answer to the numerous tracts supporting Henry's ecclesiastical claims. For this he was thrown into Beauchamp Tower, and after a year's liberation again imprisoned, in December, 1533, on the charges of disseminating the prophecies of the Maid of Kent, encouraging the queen "obstinately to persist in her wilful opinion against the same divorce and separation", and maintaining her right to the title of queen. He was kept in close confinement until his execution at Tyburn, two days after the execution of Thomas Cromwell. There is still to be seen on the wall of his prison in the Tower of London a rebus consisting of the symbol of a bell with an A upon it and the name Thomas above, which he carved during his confinement. He was beatified by Pope Leo XIII as one of a group of fifty-four English Martyrs on 29 December 1886.
There is extant a very pious Latin letter written by him to a fellow-martyr, and another to Cromwell, begging for some slight mitigation of his "close prison"; "license to go to church and say Mass here within the Tower and for to lie in some house upon the Green". It is signed "by your daily bedeman, Thomas Abell, priest". His act of attainder states that he and three others "have most traitorously adhered themselves unto the bishop of Rome, being a common enemy unto your Majesty and this your Realm, refusing your Highness to be our and their Supreme Head of this your Realm of England".
Oral, manuscript, and published traditions of resistance to the Protestant supremacy in England fueled Catholic Recusancy for centuries and the renewal coincident with the toleration of the open practice of Catholicism in the 19th century.