The Duck Dynasty family is mourning the loss of Phil Robertson.

The reality star, whose Alzheimer’s disease diagnosis was made public in December, has died, his family confirmed May 25. He was 79.

“We celebrate today that our father, husband, and grandfather, Phil Robertson, is now with the Lord,” Phil’s daughter-in-law Korie Robertson, married to Willie Robertson, wrote on Facebook. “Thank you for the love and prayers of so many whose lives have been impacted by his life saved by grace, his bold faith, and by his desire to tell everyone who would listen the Good News of Jesus. We are grateful for his life on earth and will continue the legacy of love for God and love for others until we see him again.”

“We know so many of you love him and have been impacted by his life,” Korie continued. “We’re having a private service for now, but we’ll share details soon about a public celebration of his life.”

Phil’s granddaughter Sadie Robertson also paid tribute to him online. Reflecting on their final moments together, Sadie wrote on Instagram, “One of the last things he said to me was ‘full strength ahead!’ Amen!”