Roberts spoke with Thomas' physician, Ashley Nichols, who told him Roberts would only be able to be without his oxygen tubes for a very brief period.
"Dr. Nichols made it clear he would only be able to be off oxygen for a few seconds, which meant we couldn't roll him down the ramp in the pool wheelchair, so we had to use the chairlift to place him in the pool," Agricola told UAB News.
Roberts was lowered into the pool as his wife, son, two sisters, niece and nephews watched, the website reported. Agricola read Romans 6:4-11 from the Bible but addressed Roberts before reading the passage.
"I have served in the ministry over 20 years and seven of those at UAB. This is the greatest day of my career," Agricola said, according to UAB News. "Thomas, you never thought you would preach a sermon in your life; but you preached today. You made an impact on people who you do not even know."
Agricola dunked Roberts backward to complete the baptism.
Roberts died Sept. 9, WBRC reported. He was 56.
"I don't know what could be a better gift than the feeling of peace, and that is what we have now," Brooke Carr, Roberts' niece, told UAB News.