Front of shirt: Navy SEAL motto "Only Easy Day Was Yesterday"
Navy SEALs are known as Frogmen. The bone-frog and cross is one of the ways to honor those who have sacrificed all on the battlefield for the sake of freedom.
Sleeve: American Flag
Back of the shirt: "Greater love has no one than this; to lay down one's life for his friends" carries double significance. Memorializing those that have sacrificed all for freedom sake; as well as the Savior who spoke those very words of "greater love" who sacrificed all at the cross for freedom from sin.