If the persecutions and sufferings of Saint Paul here are understood as those from his first preaching in these places, then only the beginnings of faith were being laid in Saint Timothy. If he shared in these sufferings not only in heart but also in deed, they tempered him for all later sufferings.
By recalling this beginning, or this foundation, the Apostle also reminded him of what followed. “He had no need to enumerate everything separately, because he was not vainglorious or ambitious. He spoke not to glorify himself, but to console and encourage his disciple” (Chrysostom).
But perhaps Saint Paul is not speaking here of the earliest persecutions and sufferings in these regions. He may mean recent ones, when, after returning from Rome through Crete and Phrygia, he again visited these regions on his way to Antioch.
Chrysostom, among others, thinks this: “And perhaps he mentioned only these because he is speaking of recent events, not ancient ones.” The same is repeated by Saint John of Damascus, Oecumenius, and Theophylact.
The purpose of mentioning persecutions and sufferings was to inspire unfailing courage when encountering troubles inseparable from the work of evangelizing. For this it was enough to recall briefly and generally what had happened and been experienced.
This is what Saint Paul does in the words: “what persecutions I endured.” What persecutions, indeed, did I endure! You have no need to list them. You know them yourself.
By this single brief word Saint Paul directed Saint Timothy’s mind to everything he had suffered. But where is the source of encouragement? In this: “from them all the Lord delivered me.”
“Then the Apostle mentions what and how much he suffered, to show also how great and near the help of God is. By it He defends His servants and makes them safe from the shamelessness of Satan. Through this he awakens courage and readiness always to meet fearlessly the assaults of the unbelieving and treacherous” (Ambrosiaster).
The direct conclusion from this is: take courage, then! The Lord will deliver you also. Therefore do the work of an evangelist, paying no attention to the troubles joined to it, and certainly not being disturbed by them.
“There is a twofold consolation and encouragement for you here: that I showed courageous readiness for everything, and that I was not forsaken” (Chrysostom). “You also be ready for everything, and in the same way you will never be forsaken” (Theophylact).