To say that predestination is not part of the gospel of God's Grace, is a serious mistake and contrary to scripture.
It's a serious mistake to attempt to put God into a box. God's sovereignty and man's free will go hand in hand. This mystery cannot be understood by the natural man. Those who believe in the Lord Jesus Christ are the elect of God....we hear the gospel and believe, and are then sealed with the Holy Spirit.
Ephesians 1:13 - "In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,"
God has predestined (before ordained) believers be adopted and conformed into the image of the Son.
Ephesians 1:5 - "Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,"
Ephesians 2:10 - "For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them."