Disclaimer: ‘Predestined to be conformed’ is not a proof text for certain people going to heaven no matter what.
Who are those who will spend eternity with the LORD? Is there anything that would characterize these apart from all others?
Romans 8:26-30 is one of those ‘loaded’ passages squeezing so much into so few verses:
ENABLING: We are not sufficient in ourselves but the LORD provides the Holy Spirit as our guide through what lies before us in our journey with God:
ACCOMPANYING: While not everything is from God, God is with us taking the circumstances and working them out for our benefit in His desires. We are not left without purpose or the presence of the LORD participating for His benefit in us.
CONFORMING: Christ in us should mean that we come to be His representation as we are imprinted with His likeness contacting our lives. God’s prognosis for those ‘in’ Jesus is that our boundaries bring us into perpetual contact with Him and we come to share forth His likeness.
FULFILLING: Being ‘in Christ’ is not a passive destination but rather a continued change-state wherein we are being changed from glory to glory.
Now about that ‘predestination’ thing: ‘For those whom he foreknew’ 5 precedes as the beginning of verse 29 and does mean ‘foreknew’ in the sense that beforehand God knew that those who would live in the bounds of a life in Jesus would live in His image. This is the implication of being in agreement with God’s terms of relationship with the LORD.
Anything else would be a contradiction.