For to this end we both labor and suffer reproach, because we have set our trust in the living God, who is the Savior of all men, especially of those who believe.
because we trust in the living God: The "agonizing" battle that Timothy and Paul are engaged in is not pointless either because Paul has confidence that he is fighting "the good fight" (2 Timothy 4:6), and that his captain is "the living God."