A really hard question on Satan and deception.

[Greatest I am]

God is not the deceiver, satan is, and God in His righteousness will keep safe those who accept Him from satans deceptions.

Now, therefore, behold, the Lord hath put a lying spirit in the mouth of these thy prophets, and the Lord hath spoken evil concerning thee.
1Kings 22:23

Now therefore, behold, the Lord hath put a lying spirit in the mouth of these thy prophets.
2 Chron 18:22

Ah, Lord GOD! surely thou hast greatly deceived this people.
Jer 4:10

O Lord, thou hast deceived me, and I was deceived. Jer 20:7

And if a prophet be deceived when he hath spoken a thing, I the Lord have deceived that prophet.
Ezekiel 14:9

For this cause God shall send them strong delusion, that they should believe a lie.
Thessalonians 2:11

Do you still maintain that God does not deceive?

Regards
DL