Father Gabriel had turned a new leaf with the survivors and wanted to become a more brave version of himself to help the community at alexandria and had gotten proficient at the rifle and became a sharpshooter. However, as Gabriel tried to be brave by helping the colony against a zombie attack from the Whisperers, Gabriel tripped in the watchtower, horribly breaking his leg, falling down right in front of Beta who disembowled him. One of the grosses deaths in the entire series. In the Walking Dead, your redemption arc doesn't always quite follow through and no good deed goes unpunished. Father Gabriel was a popular character on the TV adaptation as he was played by acclaimed actor Seth Gilliam famously from The Wire.
