a question

Lately I've been thinking about the promises in the Bible as they're related to the context in which they're given...in other words, how do we know when the promises are for everyone (believers) and when they're just for the people written to? I've been reading Jeremiah lately and recently came across chapter 29, probably the best known Jeremiah passage, especially verse 11 ("For I know the plans I have for you, declares the Lord, plans for peace and not for evil, to give you a future and a hope.") I would say that throughout my life as a christian, this verse has been quoted as applying to all believers. There might not be anything wrong with that - it might be a promise to all of us. God does in fact have a future for us, and a hope that endures all trials. In terms of the context though, God is speaking to the Israelites who are in exile in Babylon. Jeremiah sends a letter to these Israelites in Babylon, telling them to settle down because they're going to be there awhile, but that God will come for them after a time to bring them back to Jerusalem. Vs 10 starts: "For thus says the Lord: When seventy years are completed for Babylon, I will visit you, and I will fulfill to you my promise and bring you back to this place. For I know the plans I have for you, declares the Lord, plans for peace and not for evil, to give you a future and a hope. Then you will call upon me and come and pray to me, and I will hear you. You will seek me and find me, when you seek me with all your heart. I will be found by you, declares the Lord, and I will restore your fortunes and gather you from the nations and all the places where I have driven you, declares the Lord, and I will bring you back to the place from which I sent you into exile." (that was 10 - 14) So basically, Israel has been attacked because the Israelites would not repent from their wicked ways. Some are spared and taken to Babylon, and many are killed. At that time, it must have seemed like God had abandoned them, as King Nebuchadnezzar saw great success in conquering them. Jeremiah sends a letter to those despairing though, a letter of hope and encouragement, a promise to save the remnant of Israel.

So, is it acceptable for us to "claim" this promise as our own? Or was it written just to the Israelites at that time? I tend to lean towards it being a promise to each of us, because often I find that the words Jeremiah wrote to the Israelites could have been written to my wandering heart. "Build houses and live in them; plant gardens and eat their produce. Take wives and have sons and daughters; take wives for your sons, and give your daughters in marriage, that they may bear sons and daughters; multiply there, and do not decrease. But seek the welfare of the city where I have sent you into exile, and pray to the Lord on its behalf, for in its welfare you will find your welfare..." (vs. 5 - 7) No, I've obviously never been in exile, but I often fight with my heart for contentment, and these verses remind me to settle down because God has placed me where he has for his good will. I suppose that learning from what God tells the exiled Israelites is a little different than taking a promise meant for them for myself though. Hmm, does this make any sense? I hope so. All I'm really asking is how do we know when a promise is aimed at all of us, and how do we know when it's aimed at a specific person or people (and not us)? How do we use the context of verses to discover whom the promise is meant for? What are your thoughts?