James D. Hernando has written a brilliant piece on Spiritual Leadership, drawn from the salutations (the way Paul sends his greetings in his Epistles. )
Paul was quick to commend and free with his praise. Look how often this is the case. Phoebe has been a helper or “servant”2 not only to Paul, but also to many in the church (Romans 16:2).3 Priscilla and Aquila “risked their own necks” for Paul (Romans 16:3,4). Tryphaena and Tryphosa are called “workers in the Lord” (Romans 16:12). Mary was singled out as a hard worker (Romans 16:6), as was Persis (Romans 16:12). Paul, it seems, goes out of his way to affirm his subordinates and acknowledge their praiseworthy contributions.4
Paul fully knew and practiced the importance of relational encouragement.