Śrīla Prabhupāda: “[…] One feature of the Supreme Personality of Godhead Lord Rāmacandra is omnipotence. The Lord can act without regard to material impediments or inconveniences, but to prove that He is the Supreme Personality of Godhead and was not merely advertised as Godhead or elected by popular vote, He constructed a wonderful bridge over the ocean.

Nowadays it has become fashionable to create some artificial God who performs no uncommon activities; a little magic will bewilder a foolish person into selecting an artificial God because he does not understand how powerful God is. Lord Rāmacandra, however, constructed a bridge over the water with stone by making the stone float. This is proof of God’s uncommonly wonderful power.

Why should someone be accepted as God without displaying extraordinary potency by doing something never to be done by any common man? We accept Lord Rāmacandra as the Supreme Personality of Godhead because He constructed this bridge, and we accept Lord Kṛṣṇa as the Supreme Personality of Godhead because He lifted Govardhana Hill when He was only seven years old. We should not accept any rascal as God or an incarnation of God, for God displays special features in His various activities.

Therefore, the Lord Himself says in Bhagavad-gītā (4.9):

janma karma ca me divyam
evaṁ yo vetti tattvataḥ
tyaktvā dehaṁ punar janma
naiti mām eti so ’rjuna

“One who knows the transcendental nature of My appearance and activities does not, upon leaving the body, take his birth again in this material world, but attains My eternal abode, O Arjuna.” The activities of the Lord are not common; they are all transcendentally wonderful and not able to be performed by any other living being.

The symptoms of the Lord’s activities are all mentioned in the sastras, and after one understands them one can accept the Lord as He is.

(Śrīmad-Bhāgavatam 9.10.15 » Purport | 1977 Edition)