"With much prayer and deliberation, I have elected to officially retire from the NFL as I endeavor to devote the remainder of my life to the further advancement of the Gospel of Jesus Christ," Willis, 26, wrote in an Instagram post. "I thank all of my family, friends and those who have supported me on this journey thus far and I look forward to your continued support through the next phase of my life.
"I am both humbled and excited to pursue the holy call that God has for my life which brings me much joy and purpose. Thank you all for your support over the years ..."
Willis, a fourth-round pick in 2019, became the team's starting strong safety halfway through his rookie safety. He finishes his career with 219 tackles and four interceptions while starting 33 out of the 39 games he played in.
"We're thankful and appreciative of Khari's contributions to the Colts both on and off the field over the last three seasons," coach Frank Reich said in a statement. "Khari's character, leadership, and professionalism will be missed in our locker room as will his play on Sundays. I admire and respect his decision to transition into the next stage of his life and ministry and my prayers will always be with him."
The Colts had already addressed the safety position some in the offseason. They signed veteran Rodney McLeod in free agency and selected Maryland's Nick Cross with the 96th overall pick in this year's draft. McLeod likely has the inside track to start at Willis' spot, with Cross as the projected long-term starter there.