Question: How can a non-Calvinist explain 2 Thessalonians:2:13? Isn’t it quite conclusive that those to whom Paul wrote had been “chosen [unto] salvation” —i.e., predestined to heaven?
Answer: That scripture states, “...God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth.” Does that mean they had been predestined for heaven? Absolutely not.
The clear message of Scripture from Genesis to Revelation is that all mankind have been “chosen to salvation” by the God who would “have all men to be saved...” (1 Tm 2:4), who is “the Savior of all men, specially of those that believe” (4:10), and whose Son “gave himself a ransom for all” (2:6). The fact that one has been “chosen” to salvation does not mean that one has been predestined for heaven, but that one is a sinner, and all sinners have the opportunity to believe the gospel—which most refuse to do.
Christ said to His disciples, “Have not I chosen you twelve, and one of you is a devil? He spake of Judas...that should betray him...” (Jn:6:70-71). Clearly, the fact that Judas was one of those chosen to be a disciple did not guarantee that he would fulfill that calling. He was morally responsible to follow Christ by faith. Through his own choice, he did not do so and is now in hell.
The same biblical truth is demonstrated also in Israel: “The Lord thy God hath chosen thee to be a special people unto himself...” (Dt 7:6). That “choosing” did not automatically assure that every physical descendant of Abraham, Isaac, and Jacob would necessarily live the part. Unfortunately, Israel as a whole did not fulfill that calling but went into sin, and God had to cast her out of the land.
From these and other scriptures, it is clear that being “chosen” to salvation does not bring salvation: one must still believe the gospel in order to be saved. That fact is further made clear by the rest of the verse: “through sanctification of the Spirit and belief of the truth.” Though “chosen to salvation,” the means of salvation is not the choosing by God, but it is the individual’s “belief of the truth.”