1 Thessalonians 1:4
For we know, brothers loved by God, that he has chosen you
Before the creation:
A.
Because God love some people
that is why He choose these people
or....
B.
Because God choose some people
that is why He love these people
If there is an answer, I would like to have the verse also as the reason of the answer.
Since both the love of God for his own, and the election of God, in Christ, are an eternal matter, rather than a matter of time, I think that the question, in its present form, cannot be answered.
What is made clear in scripture is the following :
I am crucified with Christ; nevertheless I live, yet not I but Christ lives in me; and the life which I now live in the flesh I live by the faith of the Son of God, who loved me and gave Himself for me. [Galatians 2:20, KJV.]
Three things are made clear :
The reason that the Son of God redeemed Paul was because the Son of God loved Paul prior to that redemption.
The redemption of Paul was not a corporate matter, but an individual matter. Paul was not redeemed as one of an indiscriminate crowd, but as one personally known and loved.
The redemption of Paul occurred before Paul did any good works. Paul only 'now' lived by faith. Only 'now' after redemption is Paul crucified with Christ and walking in the Spirit.
Since the love is called the love 'of the Son of God' (not the love 'of Jesus') what is being drawn to the attention is the Divine and eternal love of Christ, in Deity, towards the man Paul.
If an eternal love, then a love that is not a matter of time, a love that had no temporal beginning and a love that cannot be separated (in terms of time) from other aspects of the Divine knowledge (that is to say foreknowledge) of the man Paul.
Yea, I have loved thee with an everlasting love: therefore with lovingkindness have I drawn thee. [Jeremiah 31:3, KJV.]
You are trying to make the loving and the choosing two separate issues. Really they are the same.
What does it mean to love?
Romans 5:8 nkjv " But God demonstrates His own love toward us, in that while we were still sinners, Christ died for us. "
So the work of Christ, particularly his atoning death was his primary act of love.
What then is his election? Well election is a "choosing". What did he choose us for? Look at what Paul teaches in Ephesians 1.
Ephesians 1:4-6 4 just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, 5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, 6 to the praise of the glory of His grace, by which He [a]made us accepted in the Beloved.
So we were chosen to be made Holy by the Son (Via the atoning death previously mentioned). The choosing in itself is the first expression of that love. A key doctrine of a calvinist/reformed understanding is that God did not choose us because of anything that we have done or will do. This is the "Unconditional" portion of the unconditional election.
this makes the Gospel of Grace truly by grace, and not by any merit of our own.
eph 2:8-9 For by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9 not of works, lest anyone should boast.
So to be concise, we can clearly remove option "A" from your question. With option "B" being closer to the understanding. But really the answer is that God's choosing is just the initial expression of his loving, and not really separable. His choosing and his loving are one in the same.
The best consolation we are given as to why God chose is in the above verse from
ephesians 1:5(partial) "according to the good pleasure of His will"
