Dukkha: Suffering
Dukkha names the ache built into conditioned life. "The same sufferings which we also suffer" draws the line straight: what presses on the apostle in Asia presses on the household in Corinth, since bodies tire and plans break for everyone alike. Because the trouble is common stock rather than a private assignment, one person's way through it becomes a path others can walk, like a track worn across a field.
Karuṇā: Compassion
Karuṇā is the heart's movement toward someone in pain. Comfort received here gets spent immediately, passed along the moment it arrives, so that being consoled and consoling others are one motion. Whoever has lain awake with the same fear knows how to sit beside it in someone else, which is why the affliction itself becomes the qualification.
Kalyāṇamitta: Good friend
Kalyāṇamitta is the friend who walks the path ahead of you. Beaten, imprisoned, at times despairing of life, this one keeps writing back to Corinth, and the letters are worth more for the chains behind them. A friend who has already crossed the river can tell you where the stones are, and that is the whole use of going first.
Khanti: Patient endurance
Khanti is the strength to bear hardship without the heart turning sour. "Produces in you" carries the weight: endurance grows under load and cannot be handed over ready-made, so the comfort that arrives keeps a person standing long enough for it to form. Muscle works the same way, thickening only against weight it has to carry.
Vimutti: Release
Vimutti is the mind let go of what bound it. Comfort and salvation stand together in one clause, and the smaller serves the larger: consolation steadies a person for the time it takes, while release is what the steadying is for. Bandaging a wound matters, and it matters because the leg has somewhere to walk.