Front of shirt: Navy SEAL motto "Only Easy Day Was Yesterday" 

Navy SEALs are known as Frogmen. The bone-frog and cross recognizes SEALs that have shed their blood on the battlefield for our earthly freedoms; and the Savior who shed His blood at the cross for our eternal freedoms.  

Back of Shirt: "Greater love has no one than this; to lay down one's life for his friends" with Frog-cross.