Question: Why did Hashem tell Moshe to tell Pharaoh that the Jewish people just wanted to just leave "derech shloshes yamim - a way of three days" to serve Hashem, making it sound like we were planning to come back? Indeed when we finally left, Pharaoh sent spies after us to make sure we came back, and when they saw that we kept going after 3 days, they came back to Pharaoh and told him "ki barach ha'am - that the nation had ran away". Why did Hashem have to play tricks with Pharaoh? Why couldn't he tell him straight out to let the Yidden go for-good? After all, Pharaoh had no choice in the end, either way!
Answer: Hashem wanted to leave Pharaoh with the illusion that he was the one who let the Yidden out in the end... even though he didn't have a choice. As it says in Parshas Bishalach, "vayehi bishalach Pharaoh es ha'am - and it was when Pharaoh sent out the people"... Pharaoh thought that he was the one letting them go. Because of this, the redemption still was not complete. It had to be 100% clear that it was Hashem who was taking us out. That is why Hashem played this game with him, so he should think he still had some "control" - and then he would "change his mind" and chase the Yidden. Only then was Hashem able to show that it was 100% His doing at Kriyas Yam Suf.
Our addiction is like Pharaoh. The lesson we can learn from this is that the addiction won't let us go no matter what, until our ego gets hit so many times over the head (10 makkos) that the ego/Yetzer Hara himself agrees to let the person leave the addiction. However, this is still not bi'shleimus (complete) as long as we think that "we" (the yetzer or ego) is the one that let us out of the addiction. So it may work for a while, but then Hashem causes "Pharaoh" / the addiction to come chasing after us again. In other words, as long as we left the addiction because "we" decided to, but without a complete awareness that it was Hashem who got us out, ultimately it will not hold. It will chase us down again, because we still think "we" are in control somewhat. Like Pharaoh believed that he was the one to "agree" to let us out.
Only when we stand before the Yam Suf in complete powerlessness, with the addiction chasing us from behind to enslave us forever, and with a raging sea in front of us where we "imagine" we will surely drown if we leave our addiction for good; only in such a state are we truly able to admit defeat and know that only Hashem can save us. And this is the state of awareness that Hashem wants us to reach; a point where we truly have a proper vessel for His help - i.e. to know with 100% clarity that only He can save us. And then He splits the Yam Suf and takes us out completely. "Hashem ish milchama, Hashem shemo - Hashem is the man of war, Hashem is His name".