TobyMac recalls the last text his son Truett, who died in 2019, sent him — and tells PEOPLE why he's "grateful" to have it.

TobyMac opens up to PEOPLE about writing 'Heaven on My Mind,' which was inspired by finding joy after the death of his son in 2019.

"And the last text he sent me, I don't know why this moves me so much, but he's like, 'Dad, you've always made me feel like a superhero,'" TobyMac, 60, continues. "That moved me to my core ...