it was for this that he called you

2Thessalonians 2:14 it was for this that he called you by our gospel, to gain the glory of our Lord Jesus Christ.

Context is everything. 

If I read this as a stand-alone sentence, then I would have to ask the question: 

What is the "this " that he called me for?

The word reference 'this" primarily goes back to 2 Thessalonians 2:13, where Paul wrote, "because God has from the beginning chosen you to salvation,"

Our salvation comes through a continuing process of sanctification by the Holy Spirit and our belief in the truth. The Modern King James version of this verse says: "belief of the truth,"

The truth, then, is "respecting God and the execution of his purposes through Christ,"
(Webster's )

Truth is integrated into our salvation, for we have to believe the truth, which is Christ Jesus and his word.

Salvation might well be extrapolated as:
In English Versions of the Bible, the words salvation and save are not technical theological terms but simply denote deliverance in almost any sense the latter word can have. In systematic theology, however, salvation denotes the whole process by which man is delivered from all that would prevent his attaining the highest good that God has prepared for him. (ISBE)

Because verse 13 has us being saved through sanctification, we need to look at that word more intently.

The ISBE tells us that:

"To understand this primary meaning we must go back to the word holy in the Old Testament. That is holy which belongs to Yahweh. There is nothing implied here as to moral character. It may refer to days and seasons, to places, to objects used for worship, or to persons. Exactly the same usage is shown with the word sanctify. To sanctify anything is to declare it as belonging to God."

Sealed by the Holy Spirit, we are God's after we have believed the truth. The progress along that path toward transformation (not really clear on what all that encompasses) is a constant work in progress that will only be complete upon the day that we are changed. I am sure that is debatable, and there will be those who argue that there is a chance that God will continue the change process even while in heaven. (Note that scripture tells us that nothing sinful/evil will be allowed in heaven, so that is really not likely.) A book I read about a young man returning from heaven said that Jesus taught him everything (I transliterated a little here). The implication was more of an instant download of information. That might be part of the change that we go through.

I can tell you this. I have seen more changes in me in the last couple of months than I have ever experienced in my previous 56 years. I know it is a God thing, for I am even witnessing something I enjoy now. Go figure.
Take it easy on the condemnation until you try walking in my shoes. Ask me when we meet in heaven, and I will tell you all about it. Besides, there, I will not be so apt to take a swing at you. Just kidding, I think.

Something outstanding about 2 Thessalonians 2:14 is this: "he called you to share in the glory of our Lord Jesus Christ."

I will not try to define what the glory is but think about what we know about him now.

Even when we were dead in sins, has made us alive together with Christ (by grace ye are saved;) And has raised us up together, and made us sit together in heavenly places in Christ Jesus: That in the ages to come he might shew the exceeding riches of his grace in his kindness toward us through Christ Jesus. (Ephesians 2:5-7 KJV)

Even though it seems as though we are to attempt to live in this state of euphoria, something I have not mastered, we do have the promise of God showing us what is to come. And trust me, this is beyond my imagination.

I can hardly wait.