Why do the episodes of the war with Amalek and Yisro’s arrival serve as lead-ins to the revelation at Sinai and the Decalogue?
Is it better to be shrewd or gullible?
Is there any room for skepticism in the hearts and minds of believers in the 13 Articles of Faith?
And [thus] Yehoshua weakened Amalek and his allies by the sword
— Shemos 17:13
And Yisro priest of Midyan , Moshe’s father-in-law heard about all that Elokim had done for Moshe and His people Yisrael, when He extricated Yisrael from Egypt … And, along with Moshe’s wife and sons, Yisro came to the desert where Moshe was camped near Elokims mountain.
— Shemos 18:1,5
And Yisro … heard: What news did he hear that [motivated him enough] to come? The splitting of the Sea of Reeds and the war with Amalek. —(from Zevachim 116A, and Mechilta)
— Rashi ibid
Now I know that Hashem is the greatest of all the deities, for [He came] upon them [the Egyptians] with the very thing that they plotted.
 — Shemos 18:11
Of all the deities:Â This teaches us that he [Yisro] was familiar with every type of idolatry in the world, and there was no pagan deity that he had not worshipped. (from Mechilta)
— Rashi ibid
Destroy all the places, where the nations that you are driving out served their gods, [whether] upon the high mountains, the hills, or under every verdant tree.
— Devarim 12;2
For your gods were as numerous as the number of your cities, O Judah …
— Yirmiyahu 11:13
… yet upon every high hill and under every leafy tree[traditional places of idols and their worship] you recline, playing the role of a harlot.
— Yirmiyahu 2:20
The naïf believes everything; but the incredulous understands the correct footsteps to tread.
— Mishlei 14:15
Strike the scorner, and the naïf grows shrewd.Â
— Mishlei 19:25
“Strike the scorner†this refers to Amalek “and the naïf grows shrewd†this refers to Yisro
 — Shemos Rabbah Yisro 27
I am HaShem your Elokim who extricated you from the land of Egypt, from the house of slavery
— Shemos 20:2
And he [Bilaam] gazed at Amalek, and took up his allegory, and said: “Amalek is the first among the nations; but his end shall come to eternal destruction.â€
— BeMidbar 24:20
Like fire and atomic energy; faith can be a tremendously positive and constructive or a negative and destructive force. When one has faith in HaShem, true prophets and chachmei haTorah-authentic Torah sages; it sustains and nurtures the life of the faithful, as the pasuk teaches v’tzadik b’emunaso yichyeh-and the just will live in/through his faith (Chavakuk 2:4). However, when faith is invested in false gods, false prophets and/or assorted charlatans, there is nothing more corrosive, detrimental to society and self-destructive. To carry the simile further, just as nations are better served by building safe and secure nuclear power plants than in stockpiling surplus nuclear warheads, one must be extremely judicious and discriminating in deciding what and/or whom to invest their faith in.
So, while faith can potentially be the greatest of virtues, it is not to be confused with gullibility and naïveté. Faith unleavened by healthy doses of discernment and skepticism is folly and, as Yirmiyahu the prophet implies by describing the idolatrous Jews of his era as “playing the harlot†and having as many deities as cities, a kind of promiscuity of the heart and mind. The emunah-faith; of one who has “complete and perfect faith†in the thirteen fundamental articles of Jewish belief is of diminished value if he also believes in every outlandish hoax ever publicized or if he can be swindled into buying the Brooklyn Bridge because he is convinced of the seller’s integrity. For faith in truth and belief in reality to be commendable one must first stop suspending his disbelief in mirages and repudiate the bill-of-goods that he had formerly been convinced of for the lies that they are.
At one time or another Yisro believed in every possible manner of fabrication. Chazal teach us that there was not a single pagan deity that Yisro did not worship. To buy in to so much and such varied deception means that Yisro was possessed of an extremely credulous and gullible nature. The lashon kodesh-biblical Hebrew; word that defines this kind of folly is pessi-a naïf who’ll believe anything.
At the extreme opposite pole of human nature stands the letz-scorner/scoffer who believes in nothing and no one. Such people wear their incredulous disbelief as badges of honor marking them as wiser and as sharper than the credulous. They scoff at believers, first and foremost by mocking all that they believe in. Such skeptics scorn across the board and no target is safe from their sneering, scathing “appraisals.†Such letzim are the Wildean cynics who “know the price of everything and the value of nothing.â€
Amalek is identified by Chazal as the letz incarnate. The national character of Amalek is wired to scoff and mock everything, up to and including all that is real, true and holy. How else can we understand that while all other nations were awestruck by the events of the Exodus from Egypt and the Parting of the Sea of Reeds, so much so that they had come to some level of belief in the invincibility-borne-of-chosen-ness of the Bnei Yisrael-the Jewish people; and the Infinite Power of the G-d of Israel, Amalek remained unimpressed? The preemptive attack launched by Amalek was their über-skeptical “I’m from Missouri, you’ve got to show me†moment.
The Izhbitzer explains that once letzim are inevitably set in evil ways they become irredeemable. All exhortations to tikkun-repairing ones evil; depend on getting the perpetrator to believe in the value of change and improvement. But the scoffing, scornful, skeptical letz does not recognize or tolerate chashivus-value and significance. One can try to rehabilitate the letz with both high-minded arguments and/or corporal-punishment “convincing†and both will be wasted on those who know the value of nothing. On the other hand, when dealing with a pessi there is someone to talk to and something to work with. The ethical challenge of the pessi is that he believes in the value of too many things. Discernment and a healthy dose of skepticism come with experience and education, sometimes even from education gleaned from the lessons and exhortations wasted on the letz.