The grace of repentance, which acts in those who struggle, is a patristic inheritance. It is a divine transaction and exchange in which we give dust and receive heaven. We exchange matter for the Spirit. Every drop of sweat, every pain, every ascesis for God is an exchange.
The temptation comes in accordance with one’s stature. And you must endure in order to emerge victorious. Christ, Who sets the contest, allows temptations for this reason: so that we may gain victories against the enemy, be purged from passions, and be perfected.
When can someone understand human suffering? When he also suffers. When he goes through the same, he learns and understands the other person's suffering. Otherwise, he is callous and is not grieved, unless he happens to have a good nature. But all natural attributes merit neither honor nor dishonor; achievements and falls depend on our own free will.
Go, sell all that belongs to you and give it to the poor and taking up the cross, deny yourself; in this way you will be able to pray without distraction.
Do all in your power not to fall, for the strong athlete should not fall. But if you do fall, get up again at once and continue the contest. Even if you fall a thousand times because of the withdrawal of God's grace, rise up again each time, and keep on doing this until the day of your death. For it is written, 'If a righteous man falls down seven times' - that is, repeatedly throughout his life - 'seven times shall he rise again' [Prov. 24:16].