Roman Catholic
What they teach
Justification begins with grace received in baptism and grows through faith working in love, the sacraments, and good works done by grace. Grace can be lost through mortal sin and restored through confession. Most believers cannot be certain of final salvation.
The Free Grace answer
Grace that must be maintained by works is no longer grace (Romans 11:6). God justifies the one "who doesn't work, but believes" (Romans 4:5). Jesus said the believer already has eternal life and will not come into judgment (John 5:24). That leaves no room for losing it through mortal sin, and no need for purgatory, because Christ perfected believers forever by one offering (Hebrews 10:14).