Question:
Answer:
The short answer is to stay in right relationship with Jesus Christ and his Catholic Church and to repent and receive the sacrament of reconciliation if you stray into mortal sin (cf. CCC 1854-64).
Indeed, our free-will choices make a difference. As St. James makes clear, “You believe that God is one; you do well. Even the demons believe—and shudder” (James 2:19, emphasis added). So it’s not simply enough to believe in God’s existence. We have to respond and accept his free gift of salvation. We do this by our choices, our “good works.” As the word gift implies, we don’t—we can’t—earn our salvation, but we must freely cooperate with God in being saved, and we do so through our everyday choices.
That’s why James could add, “Some one will say, ‘You have faith and I have works.’ Show me your faith apart from your works, and I by my works will show you my faith. . . . [So] you see that a man is justified by works and not by faith alone” (James 2:18, 24).
James was only concurring with Christ:
“Not every one who says to me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven. On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you evildoers’” (Matt. 7:21-23).
For more on the issue of salvation and our cooperation, see CCC 846-48.