One word possibly could describe this book “comforting.” Paul had written very strongly in his first letter to this assembly. Now he has heard that it had had a good effect on them, so he writes his second letter to them.
V.3-4 There is no comfort like that which comes from God Himself, and Paul had himself felt the wonder of this. And now he is able to comfort others. Let us not be afraid of trials but turn to the Lord for the lessons intended and for the comfort that comes with the trials. And then we shall be better able to encourage others who are in trial.
V.11 It is good to help the work of the Lord by prayer. When souls are saved, we can then feel that we’re part of the work.
V.14-19 Paul wanted to visit them, and because he didn’t get there, they accused him of changing his mind.
V.20 God always keeps His promises! Paul is saying that when he said “yes,” he meant “yes,” “yea” (certainly) and “amen” means “Let it be done.”
V.21-22 The Holy Spirit of God is given to every believer for 3 special purposes (1) “anointed,” so that we may be able to understand the truth; (2) “sealed,” so that we may be sure we are eternally saved; (3) “earnest,” by having the Holy Spirit actually living in our body, we have the guarantee that we are a child of God.