Salvation is by grace through faith in the purifying mercy of God. The most important thing to say is that it is a life of confidence in God. Which simply means that life in the refiner's fire is a life of trust in the unchanging, purifying love of God. And perhaps the next most important thing to say is that there is no painless path to heaven. And it is no more possible to become pure painlessly than it is to be burned painlessly.
Purity comes through the refining fire.
And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing. My son, do not regard lightly the discipline of the Lord . . . If you are left without discipline, in which all have participated, then you are illegitimate children . Pursue holiness without which no one will see the Lord. And the other form of purifying fire is the fire of intentional self-denial.