Randy Travis stunned millions of fans when he made a surprise appearance at the 2015 ACM Awards on Sunday night (April 19).

The singer, who was introduced by Lee Brice, stood and waved to a thunderous standing ovation, following Brice's performance of Travis' "Forever and Ever, Amen." After his appearance, however, Travis, who suffered a stroke that left him unable to speak in 2013, penned a heartfelt letter to his fans on his website.

Hello, my friends. It was an amazing gift to feel all the love from you in Dallas at the Academy of Country Music Awards. It has been a hard-fought and miraculous journey since my stroke two years ago, and I have gained a greater understanding of God's grace, and how quickly events can change us.

Words can never express my gratitude to those who continue to believe in me, pray for me and keep me lifted up in thought and deed. The kind cards and heartfelt letters of testimony and encouragement brought me through the darkest of days. Mary read each and every one of them to me, and I felt the love and concern being sent my way; and, I gathered strength from this. None of us are worthy of the immense outpouring of support shown to me, and I consider each of my fans, a friend. Thank you from the bottom of my heart.

The power of music remains a source of inspiration and healing for me. Writing songs was always a passion of mine, and I still have a lot to share with you. It is my prayer that, with continued healing, one day soon, I will be back on that stage exchanging music with my fans ... my friends, who with God's amazing grace, have brought me this far. As I work through music/speech/occupational/physical therapy, it is my hope that my songs of yesterday continue to touch your life in some way.

I wish you each -- good health, a kind word, a song in your heart, and a friend that has your back trough thick and thin.

My gratitude & love, "Forever and Ever, Amen"

The 10-time ACM Award winner was accompanied to the awards ceremony by his fiancee, Mary Davis, who has stood by him throughout his illness and recovery.

"Randy's history with the ACM awards goes back over two decades," she tells People magazine. "With the awards in Dallas and celebrating 50 years, it's something Randy and I would not miss."

Randy Travis Through the Years

5 Lessons We've Learned From Randy Travis

More From TheBoot