Then said I, Ah, Lord GOD! surely thou hast greatly deceived this people and Jerusalem, saying, Ye shall have peace; whereas the sword reacheth unto the soul.
It doesn't say God lied, it says He deceived the people (deceive being, to intentionally trick or mislead somebody: to mislead or deliberately hide the truth from somebody).
I think perhaps the "Ye shall have peace" wasn't meant for the immediate future, but the people took it that way. It doesn't say "Ye shall have peace tomorrow" or "Ye shall have peace next year".
Like, if I told some kid I would buy them ice cream if they sat still in church, and they were like, "oh boy!" But after church I had them eat brussels sprouts first, they might say "You tricked me!".