Predestinated to Faith in Christ !
Those who come to Faith in Christ were predestinated thereunto, whereby we read in Eph 1:4-5
4 According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love:
5 Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,
Predestinated to the adoption of Children or Sons by Jesus Christ ! The word for Children is actually the greek word huiothesia made up of Two words tithēmi :
I.to set, put, place
And the word huios :
I.a son
Hence to set or place as a Son through or by [dia] Jesus Christ !
And we are declared to be the Children/ Sons of God by Faith in Jesus Christ Gal 3:26
26 For ye are all the children of God by faith in Christ Jesus.
Yes that word children here is the same greek word huios = Son !
And its because we were always Sons secretly even in Adam Lk 3:23, because of the Work of Christ to deliver us from the fall in him, The Spirit of Adoption is sent into our hearts to declare our Adoption Gal 4:6
And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.
And with the Spirit is effected the Fruit of Faith Gal 5:22 by which we come to Faith in Christ Jesus Gal 3:26.
Also Gal 4:6 is the fulfillment of the Covenant Promise to Ezk 36:26-27
26 A new heart also will I give you, and a new spirit will I put within you: and I will take away the stony heart out of your flesh, and I will give you an heart of flesh.
27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.
All of this was Predestinated by God according to His choosing us in Christ before the foundation