The context affirms our reconciliation with God through Jesus Christ. It is through His shed blood that we obtain redemption, and as stated in verse 11, an inheritance.
The text also indicates that we obtain that inheritance as those who are “predestined according to the purpose of Him…” This refers to God, and it was His plan before the creation of man to redeem (our “adoption as sons”, cf. verse 5) through Jesus Christ.
In other words, God chose before the foundation of the world those who would go to heaven. His choice was that those who believe would be redeemed (cf. Mark 16:16). Predestination here refers to the group God chose to save. It is your choice whether you wish to be a part of that group.
For those who are predestined, those who are a part of that group, salvation is surely promised by our God.
