"I have never lost a friend. In this difficult time, I am leaning on all of the wonderful memories we shared with Cory, how many ways he was able to make us smile," Dianna Agron, who played Monteith's onetime girlfriend on the hit show, says in a statement obtained by PEOPLE.
"Glee was a gift to all of us. It gave us a family in this industry. We really cut our teeth and grew up on this show. In playing underdogs, we learned that we had dug into the hearts of our viewers and that we could stay there."
"Cory is so deserving of that place in everyone's hearts. He was one of the most generous and kind people that I have ever met. He had a smart, curious mind, he was an enormous talent. He was loving to not only me, but my family," Agron, 27, continues.
"My heart goes out to his family, to Lea, to everyone that is struggling with the loss of our friend. We will miss you Cory. We will always carry a piece of you with us.”
Reps for Monteith's costar and girlfriend of more than a year, Lea Michele, released a statement Tuesday thanking family, friends and fans "for all the love and support she's received" since Monteith's passing.
Fans of Monteith's may make donations in his name to three charities that were especially important to him: Project Limelight Society, which exposes youth living in Vancouver's Downtown Eastside to the arts; Virgin Unite, founded to support entrepreneurial efforts to better the world; and Chrysalis, which helps homeless and low-income individuals find employment.