lohāgni nyāyaḥ (iron and fire)
To make something useful, and beautiful from iron, the iron ought to be put into the fire so that the smith can work with it. As a side effect, iron also acquires the same property as fire.
Śrī Hari. If this inert piece of iron, like us, is again put back into the fire, it can be transformed practically to any desired shape, plus it manifests the same fiery potency as the original fire because that potency is indeed hidden in it. By contact with Kṛṣṇa, His teachings, His name, and representatives, we are again revitalized, being able to remember our original form, full of immense transcendental energy, far beyond material limitations. This human form is giving us a rare chance to put ourselves into the fire of Kṛṣṇa consciousness.