Former NFL star Tim Tebow has paid tribute to Ravi Zacharias after hearing news that the Christian apologist has terminal cancer. Tebow, an outspoken Christian himself, struggled to hold back tears as he spoke of the profound impact Zacharias has had on his walk of faith. 

"I think it's really important in life to have heroes, and especially in the faith, and one of my heroes of the faith is a man named Ravi Zacharias. He's not doing very well,” Tebow explained in a video posted to Instagram. “So one, I would like to ask you to be praying for him. And two, I know Ravi has inspired me and millions of people around the world, so if he's someone that has inspired you, I would like for you to please write a sweet caption on this, because I would love to be able to show this to him and his team."

Many responded to Tebow's post with messages of support for Zacharias. "I feel you. Devastated. Heartbroken," wrote pastor and "Passion Conference" founder Louie Giglio. 

Seattle-based megachurch pastor Judah Smith added: "Thank you for this! I have never met Ravi but his words have affected me so deeply."

On Friday, Ravi Zacharias International Ministries (RZIM) CEO, Sarah Davis, revealed that Ravi's cancer - which was originally confined to a tumour on his spine - was extremely aggressive and had metastasized, meaning that "no options for further treatment remain."

Davis, who is also Zacharias' daughter, added: "Medically speaking, they have done all they are able.

She continued: "We know that God has purposed and numbered each of our days, and only He knows how many more Ravi will experience on this earth. 

"One day, likely sooner than later, we will be serving without our beloved founder, though I know his love and legacy will convict and inspire us to service of his Lord even greater than we have seen before. While we are full of so many emotions, we are also at peace, resting in the truth that God knows all and sees all and is sovereign and good. I think of the great joy my dad will have, and I am comforted."