Respect Thor, the God of Thunder:

Ragnar fears no god save for Thor, as no force, human or divine, could be reasonably compared to him:

He therefore feared the might of no supernatural prowess, save of the god Thor only, to the greatness of whose force nothing human or divine could fitly be compared.

Source: Gesta Danorum

Thor swings his club (hammer) Mjölnir, shattering all the interposing shields and armors. No man could resist the force of his blows and still live, and bodily masses are helpless:

However, Thor was swinging his club with marvellous might, and shattered all interposing shields, calling as loudly on his foes to attack him as upon his friends to back him up. No kind of armour withstood his onset, no man could receive his stroke and live. Whatsoever his blow fended off it crushed; neither shield nor helm endured the weight of its dint; no greatness of body or of strength could serve.

Source: Gesta Danorum

Thor is equated to Jove (Jupiter):

That they were identic with the classic gods he is inclined to believe, but his difficulty is that in the week-days we have Jove : Thor; Mercury : Woden; whereas it is perfectly well known that Mercury is Jove's son, and also that Woden is the father of Thor—a comic "embarras".

Source: Gesta Danorum

Thor's strength and prowess exceeds that of all living things:

For this reason must he be called Allfather: because he is father of all the gods and of men, and of all that was fulfilled of him and of his might. The Earth was his daughter and his wife; on her he begot the first son, which is Ása-Thor: strength and prowess attend him, wherewith he overcometh all living things.

Source: The Prose Edda: Gylfaginning

Thor lifts the Midgard Serpent (which coils around the world) almost to heaven:

"And again he said: 'It seemed to me not less noteworthy when thou didst lift up the cat; and to tell thee truly, then all were afraid who saw how thou didst lift one foot clear of the earth. That cat was not as it appeared to thee: it was the Midgard Serpent, which lies about all the land, and scarcely does its length suffice to encompass the earth with head and tail. So high didst thou stretch up thine arms that it was then but a little way more to heaven.

Source: The Prose Edda: Gylfaginning

Thor is the strongest of all the gods and men:

Then said Gangleri: "What are the names of the other Æsir, or what is their office, or what deeds of renown have they done?" Hárr answered: "Thor is the foremost of them, he that is called Thor of the Æsir, or Öku-Thor; he is strongest of all the gods and men.

Source: The Prose Edda: Gylfaginning

When Thor receives his hammer, Mjölnir, it is revealed that he can smite anything as hard as he so desires, and the hammer will not fail him. Thor can throw Mjölnir at anything, and it would strike without fail, never missing and never flying so far that it cannot return:

Then he gave the hammer to Thor, and said that Thor might smite as hard as he desired, whatsoever might be before him, and the hammer would not fail; and if he threw it at anything, it would never miss, and never fly so far as not to return to his hand; and if be desired, he might keep it in his sark, it was so small; but indeed it was a flaw in the hammer that the fore-haft was somewhat short.

Source: The Prose Edda: Skáldskaparmál

Thor's strength is so great it threatens the universe itself:

It seems obvious that Útgarða-Loki's giants were terrified for the same reason that Hymir was: Þórr's strength is great enough to threaten the very structures which hold the universe together.

Source: https://notendur.hi.is//eybjorn/ugm/hymir/hym24.html

When Thor strikes Jörmungandr with his hammer, the earth itself shrinks as icebergs resound and caverns howl from the force of the blow:

Drew up boldly

the mighty Thor

the worm with venom glistening,

up to the side;

with his hammer struck,

on his foul head's summit,

like a rock towering,

the wolf's own brother.

The icebergs resounded,

the caverns howled,

the old earth

shrank together:

at length the fish

back into the ocean sank.

Source: The Poetic Edda: Hymiskviða

Thor is the strongest of all gods and men, quelling all things quickly, with the hammer Mjölnir, the belt of strength Megingjörð (the best of all strength belts, which increases his strength by half), and iron gloves Járngreipr (which are required to handle Mjölnir):

The daughter and wife of Odin was Earth, and of her he got Thor, him followed strength and sturdiness, thereby quells he all things quick; the strongest of all gods and men, he has also three things of great price, the hammer Mjölnir, the best of strength belts, and when he girds that about him waxes his god strength one-half, and his iron gloves that he may not miss for holding his hammer’s haft.

Source: The Völsungasaga

He has also three things of great price: one is the hammer Mjöllnir, which the Rime-Giants and the Hill-Giants know, when it is raised on high; and that is no wonder, it has bruised many a skull among their fathers or their kinsmen. He has a second costly thing, best of all: the girdle of might; and when he clasps it about him, then the godlike strength within him is increased by half. Yet a third thing he has, in which there is much virtue: his iron gloves; he cannot do without them when he uses his hammer-shaft.

Source: The Prose Edda: Gylfaginning

Thor revives his two goats Tanngrisnir and Tanngnjóstr after slaughtering them for a meal:

Thor tarried there overnight; and in the interval before day he rose up and clothed himself, took the hammer Mjöllnir, swung it up, and hallowed the goat-hides; straightway the he-goats rose up, and then one of them was lame in a hind leg. Thor discovered this, and declared that the husbandman or his household could not have dealt wisely with the bones of the goat: be knew that the thighbone was broken.

Source: The Prose Edda: Gylfaginning

Thor unleashes his wrath, burning the skies, battering the ground with hail, and practically splitting apart the earth. Mountains shake and rocks smash and heaven burns as a result of Thor:

All the hawks’ sanctuaries (skies) found themselves burning because of Ull’s stepfather (Thor), and the ground all low was battered with hail, when the goats drew the temple-power (Thor) of the easy-chariot forward to the encounter with Hrungnir. Svolnir’s widow (Jord, earth) practically split apart. Baldr’s brother (Thor) did not spare there the greedy enemy of men (Hrungnir). Mountains shook and rocks smashed; heaven above burned. I have heard that the watcher (Hrungnir) of the dark bone (rock) of the land (sea) of Haki’s carriages (ships) moved violently in opposition when he saw his warlike slayer.

Source: The Ásatrú Edda: Sacred Lore of the North

Thor creates a star out of a toe by throwing it into the sky:

A toe was sticking out, so Thor broke it off and threw it up into the sky to make the star Aurvandilstá ("Aurvandil's Toe").

Source: Norse Mythology: A Guide to Gods, Heroes, Rituals, and Beliefs