Chrysostom understands it so: "Having said, 'put on and arm yourselves,' the Apostle prepares the armor and shows whence faith, hope, and love are born, and how they become the strongest weapon.
He does this when he adds, 'for God has not appointed us,' and what follows."
"Has not appointed us." God did not will that we become Christians, believers in the Lord, for that purpose. Such is not God's decree and intention concerning us. Such is not our appointed end.
"To wrath." This means either the coming wrath (1 Thess 1:10; Mt 3:7), that is, condemnation after judgment to eternal torments, or generally the state of being under God's displeasure.
"God did not call us in order to hand us over to punishment" (Theodoret). "God did not appoint us to bear His wrath" (Theophylact), "to experience His wrath" (Oecumenius).
"But to obtain salvation." That is, that we might receive salvation.
The Greek περιποιησις, according to present usage, means a feast or banquet. Thus "to obtain salvation" would mean "to the banquet of salvation."
It is the same as in the Epistle to the Hebrews: "to the saving of the soul" (Heb 10:39).
According to ancient usage, however, this word more properly means possession, acquisition by purchase.
"'To obtain salvation' means 'to acquire salvation.' He acquired us for Himself. He bought us, giving for us the highest price, the blood of His Only-begotten Son.
Having such proof of God's love for us, let us have faith in Him, love toward Him and toward our neighbors, and good hope that He will save us, whom He bought so dearly" (Oecumenius).
"Through our Lord Jesus Christ." For "there is salvation in no one else" (Acts 4:12).
All have sinned and fall short of the glory of God. Now, if any are saved, they are saved "through the redemption that is in Christ Jesus.
God set Him forth as a propitiation by faith in His blood, to show His righteousness, because of the remission of sins previously committed" (Rom 3:23-25).