Before the Rapture of the world's millions of Christians, Bruce was assistant pastor at New Hope Village Church, serving with the then-senior pastor Vernon Billings. He has doubted his faith for most of his life; though Bruce professed a belief in Christian values, he didn't truly believe in his heart until the Rapture occurs, claiming his wife and three children. Bruce almost falls into depression and disbelief, blaming himself for their deaths and realizing that he had been weak in his faith. Despite his losses, however, Bruce is determined to start anew, going to New Hope church that night and meeting Loretta and a few other members who had also been left behind. He finds his former pastor's video made to be played after the Rapture. From watching the video Bruce learns that it is not too late for him to be saved, and he commits his life to God.
He befriends Rayford Steele, who he supplies with a copy of the video, his daughter Chloe, and Cameron "Buck" Williams, and together they form an inner core group, "Tribulation Force". Their mission is to help the lost find Christ and prepare for God's Judgement that would follow the peace between Antichrist and Israel. Bruce acts as a spiritual mentor and adviser to the Tribulation Force, explaining the foretold prophecies of what is to come in the final days. Their study reveal that the peace covenant with Israel would mark the beginning of the seven years' war with Antichrist, known as the Tribulation. Bruce also befriends and becomes a spiritual mentor to four young pre-teenagers named Judd, Lionel, Ryan, and Vicki whom would eventually form an inner core group known as the Young Tribulation Force.
After returning to the U.S. from a mission trip, Bruce is killed by the Red Horse of the Apocalypse when World War III breaks. Bombs hit the hospital that he was admitted in for over-seas bug that stopped his world wide encouragement of "Tribulation Saints". Barnes was the first of many casualties the Tribulation Force suffers during seven years of war. Even though Bruce is killed relatively early in the Tribulation, the Force he helped establish becomes a driving presence during the war. It is hinted later in the series that Bruce was poisoned by Nicolae Carpathia's agents and may have died prior to the actual bombing.
He is resurrected at the Glorious Appearing. In the Millennium World, he and his wife go with Rayford's missionary trip to Egypt and help spread the gospel. He is present at the final battle of the Millennium, watching from a safe distance in Jerusalem with the rest of the Trib Force.