In his younger years as a Preacher, Abernath served aboard an Imperial Navy warship. When not preaching he walked the warship's lower decks in search of injured people to save and that is how he came across the severely injured chain gang leader Josef Khoriv. The stomach stab wound Khoriv had would have been fatal, had Abernath not used his influence to have the gang leader taken to a Butcher-Brig medicae wing. It was where the warship's higher-rated crew sought treatment and this was the only reason that Khoriv survived his stabbing. When the gang leader awoke, the Preacher was there and explained their meeting came about and that of the twenty-five wounded souls Abernath found, only Khoriv had survived. The Preacher felt that meant the Emperor had found some worth in the gang leader and because of his heavily muscled build, Abernath sought to have Khoriv become a member of the warship's Naval Armsmen. While the Armsmen would not normally allow members gun deck members to join their number, Abernath had an understanding with warship's mid-port decks Master-lieutenant-at-arms to bypass this. Khoriv agreed and this changed the path of his life dramatically, as being an Armsmen, later led him to become a Drill Abbot who served Inquisitor Covenant.
Despite his life changes, Khoriv and Abernath remained close friends, though some thirty years would pass after they last saw each other. By that thirtieth year, Abernath was a Cardinal who was among numerous high-ranking Ecclesiarchy members who were conducting a Tour of Faith across the worlds of the Caradryad Sector. This had been planned for five years, and was designed to put an end to the rising violence and rebellion that was slowly rising across the Sector. It was to take ten years to complete, but Abernath's part in the Tour ended on the holy world Dominicus Prime. Shortly after he began preaching from a dais in front of a large crowd of pilgrims, they all rushed forward to hear his words. It was at that moment, the Cardinal saw a dying pilgrim on the ground, who was using the last of her life to look up at him. For reasons unknown, the sight cast Abernath's mind into the Desolate City, while his body still remained on Dominicus. In this new realm, he traveled through the vast ruins of an Imperial city, that spread as far as the Cardinal could see. However he soon began hearing pleas for aid, which led to the center of the city and a figure sitting on a throne. It was in terrible pain, which Abernath could feel, and the figure kept repeating "I cannot go on". Once he came closer, though, Abernath knew at once that it was the Emperor upon the throne, who was crying out for aid and just before the vision of the Desolate City was gone, he heard the Emperor plead, "Please… I must be free." Abernath then found himself back on Dominicus, where only moments had passed for everyone else. However the experience had changed the Cardinal forever, as seeing the Emperor in pain and pleading for help, made the Cardinal realize the Emperor was dying. This revelation not only shattered Abernath's internal strength, but also destroyed his faith in the Imperial Creed.
Abernath was left with a feeling of despair that never ended, though he kept what he saw to himself at first. This later changed, when the Caradryad Sector began being struck by Warp Storms, dreams, wild omens and darkness that ate its stars. Abernath became convinced these phenomena were connected to his revelation and then began preaching to small groups about the Desolate City and how the Emperor was dying. The Confessors Nissena and Gardula were among them and his heretical words soon led the Ecclesiarchy to charge Abernath with Heresy. The now formal Cardinal was imprisoned in Bakka's Dungeon of the Doubted afterwards, where he admitted his guilt. Abernath then gave a confession which also contained everything he saw in the Desolate City - except for the Emperor's request to be freed. Bakka's Court of Purity, then found him guilty of his crimes and sentenced Abernath to undergo Arco-flagellation. Now forever broken by what he had seen, the formal Cardinal willingly accepted his fate, for both his Heresy and for no longer having the faith needed to serve the Emperor. However all this was found out by an operative of Inquisitor Covenant, who informed the Inquisitor of what had befallen Abernath. In turn, Covenant informed Khoriv of Abernath's Heresy and the Drill Abbot was left in shock and disbelief. The Inquisitor then informed the Abbot that they were going to Bakka, so Khoriv could meet with Abernath. This was both due to their friendship and because the Cardinal's Heresy was connected to the Desolate City realm, that the Inquisitor had long been hunting for. Others had seen this realm as well and Covenant feared its increasing appearance, would bring about the downfall of Mankind.
Upon meeting Abernath in his cell within the Dungeon of the Doubted, Khoriv implored his old friend to tell him everything. The formal Cardinal mostly did so, but only informed Khoriv of the Emperor's last words to him, after the Drill Abbot pressured him for anything that was left out of his confession. With that, Abernath was done and once more admitted his guilt to Khoriv. The formal Cardinal then remarked that though he knew the Abbot wished to save him, Abernath did not want his old friend to interfere on his behalf. He was guilty and was ready to accept his punishment. Khoriv accepted this and later left to report everything to Inquisitor Covenant. Despite Abernath's plea not to, Khoriv asked Covenant to help his old friend. The Inquisitor refused to interfere with the Ecclesiarchy's judgment of the formal Cardinal. While he admitted, Abernath was a good man, Covenant stated the formal Cardinal was guilty and had accepted the punishment of Arco-flagellation. The Inquisitor then remarked they would soon travel to Dominicus Prime and use Abernath's information to aid them in their search for the Desolate City. Khoriv reluctantly accepted this, but implored Covenant to ask the Ecclesiarchy for possession of Abernath, once his punishment was carried out. The Inquisitor agreed and soon the formal Cardinal, who was now known as Credo 425, became part of Covenant's retinue.