"He that trusteth in the Lord shall not fear when God shall judge all with tormenting fire." (From the second Antiphoy of the Resurrectional Anabathmoi in tone eight).
Notice that "all" will be judged with tormenting fire. In St. Mark's Gospel (9:49) Jesus says that "everyone will be salted with fire." The question is not if, it is when--and what you will do when you experience fiery torment. The promise of this verse that we will pray in matins tomorrow is not a promise for some future rescue after our death, but it is a promise for God's help and deliverance from fear when we face tormenting fire now, in this life.
It seems we are always surprised when doing the right thing (the Christian thing, the holy or godly thing) involves fiery suffering. Self control, for example, often involves a kind of suffering that is often (at least in confession and in the writings of the fathers) compared to fire. Desires can be burning. And the trial we experience as we choose to suffer rather than to obey the desire, this is the judgement of tormenting fire.
It is unfortunate that our culture has taught us to read the words of Christ which speak of hell and fire as something merely future. I find it very interesting that only once (Matt 5:22) does Jesus refer to the "fire of hell" (Gehenna). The other two references (Matt. 18:9 and Mark 9:47) are to the "hell of fire." That is, the hell is an attribute of fire, of torment. Therefore we might say that any time one is enduring a fiery trial, one is experiencing a bit of Gehenna, the hell of fire. And in the midst of that fiery trial, judgement or temptation, one may trust in the Lord. And trusting in the Lord, one will be delivered from fear.
Much of the time, we succumb to temptation because we are afraid that we cannot endure the pain--the pain of unfulfilled desire (and the bodily discomfort that may accompany self-control), and the fear that whatever resources God has given us or will give us will not be enough. Fear pushes us over the edge. Fear makes it too much to bear.
But those who trust in the Lord, we are taught by the hymn of the Church, will not fear when the tormenting fire judges us.
Every temptation and our response to it is a judgement. It is a judgement in the sense that it reveals what's really there. Failing the trial, falling into sin, is not the worse thing that can happen. The worse thing that can happen is not to accept what has been revealed, to blame someone or something else. If a fiery trial reveals that we are sinners, then we can turn to the Lord, who came to save the sinner. And turning to the Lord, we learn to trust the Lord. And trusting the Lord, we are delivered from fear and can endure better the fiery torment next time it visits us.