[2] Crowder attributed his influences in making the music on the album to the Southern hip hop scene in Atlanta, as well as books such as Slave Songs of the United States, African American Heritage Hymnal and others.

[3] According to Timothy Monger of AllMusic, the sound of the album as ranges from "porch-stomping folk and country to electronica, hip hop, and more straightforward worship pop.

"[6] Michael Weaver of Jesus Freak Hideout observed that while "I Know a Ghost has some of that same swamp rock sound," it's "overwhelming musical theme here is hip-hop.

"[5] "Golgotha Hill (King of Love)" is "an acoustic guitar led slow ballad,"[5] with "a little of that hip-hop feel,"[7] which narrates "a graphic depiction of Jesus being whipped and tortured on the way to the cross.

"[8] "Crushing Snakes" has a "trap-like beat" while the singers conjure up "images of warriors ready for battle as we face the world with God on our side knowing He has the ultimate victory in the end.

[7] "No Rival" is an "electronic prominent guitar led mid-tempo ballad,"[5] which "has reverberations of native African chants with the call and response from Crowder and a choir of male voices.

[7] "The Sinner's Cure" is a song that "runs the gamut from piano balladry to heavy rock to EDM,"[8] which "prompts your heart to ponder the big questions in life that we all can struggle with at times as you come to God in prayer.

[17][18] Jonathan Andre in his 365 Days of Inspiring Media review opined that despite the length of I Know a Ghost, he enjoyed the album, although some tracks would be better suited on a deluxe edition or digital only release.

[5] CCM Magazine's John Barber gave a favourable review of the album, saying, "I Know a Ghost is a powerful collection of Crowder at his very best, pulling from varied styles to make a record that feels the haunting of the Holy Spirit all over it.

"[19] Kelly Meade indicated her praise in a review at Today's Christian Entertainment, commending Crowder for his eclectic approach to music, saying "I Know A Ghost offers all of this and more as it takes you from celebrating the joys of life to deeply reflective moments that urge you to pause and focus on your relationship with your Savior and time spent with Him.