How can you attain salvation before you're in heaven?
You can be secure in Jesus. You don't have to wonder if you are good enough or if you can maintain a certain amount of works. You don't have to wonder if you will go to purgatory or worry that the Pope or some other tall hat will pronounce you unfit. You don't have to worry about God taking away the gift of faith. It was never your faith in the first place, you never earned it, and it is secure.