Lee is also a prolific songwriter, writing many of Third Day’s signature songs, including “Show Me Your Glory” (2003 ASCAP Christian Song of the Year), “Sky Falls Down” (GMA Rock Song of the Year), “Alien”, and “Wire”. He has also written songs for numerous other artists, including Kutless, Sara Groves, and Kim Hill. In 2017, Lee fulfilled a life-long goal of becoming an author, releasing his debut memoir Hurt Road through Revell Books, and going on a 30-city tour to support it.
2018 marked the turning of a page of sorts, with Third Day embarking on a Farewell Tour. To commemorate the occasion, and to launch this new chapter of his career, Lee released his debut EP Unshakable Heart in May 2018.