“Scripture indicates that God has predestined certain people to go to heaven (Rom. 8:28–30), so I’m either one of them or I’m not. Either way, I don’t need to do anything with respect to my salvation. I can simply await my fate.”
This misunderstands the nature of predestination and the role of free will.
First, predestination involves both the end and the means by which the end is accomplished. Heaven may be the end—the destination—but the means of getting there is accepting God’s offer of salvation. God doesn’t predestine people to go to heaven regardless of what they do. Heaven may be where they are going, but God has also ordained that they arrive there because they respond to his grace.
Therefore, if you are predestined to go to heaven, you will respond to God’s grace. At some point before death, you will accept his offer of salvation, and so you cannot just await your fate. Whether you go to heaven or hell is dependent on your response to God’s initiative of grace. Your actions do count.
Second, predestination includes free will. From his vantage point in eternity, outside of time, God is aware of all the free-will decisions that are made by creatures in time. Consequently, he is aware whether you will freely choose to accept or reject his offer of salvation, and he includes this in establishing predestination.
The Catechism of the Catholic Church states: “To God, all moments of time are present in their immediacy. When therefore he establishes his eternal plan of ‘predestination,’ he includes in it each person’s free response to his grace” (CCC 600).
Because your free choice determines whether you go to heaven or hell, we can therefore say: “God predestines no one to go to hell; for this, a willful turning away from God (a mortal sin) is necessary, and persistence in it until the end” (CCC 1037).
Predestination thus does not involve a denial of free will. Neither does it provide an excuse to sit back and neglect our salvation. On the contrary, man’s freedom is included within the scope of God’s plan of predestination, and if we wish to be with him in eternity, we must respond to his initiative of grace and accept his offer of salvation.