Yes their is a God & only one God.
Yes He does answer prayers and move on the behalf of those who trust and love Him, that have excepted Jesus as there Lord- Jesus is our only mediator in between man and God. It is because of Jesus sacrifice on the cross that we can boldly with confidence call on, pray to, and follow God. God moves on His promises, word and is faithful to do as he said- God isn't a wishing well he only does what lines up & is in accordance to his word - but all of the plans he has for us is good- to give us life & protection. God has even said in his word that he want intercessors on earth praying his will to be done in Jesus name.
The part where you say His chosen people- What you need to understand is that the ones that are chosen are the ones that answered God and come to Him through Jesus Christ, asking & receiving His Holy Spirit through prayer in Jesus name.
It's not like God says I chose you, you, and not you -But He is offering us the same rights through Jesus to everyone. So it's not like he is excluding anyone at his will but at there will.
How would any of us really get to know what God can and is willing to do with out stepping out their and seeking, trusting, and asking God for the things he promises?
How do you take a free gift if you refuse to open it? God expects us to seek him and believe that he wants to have a real relationship with us.
God isn't this unreachable, non-communicating God that hides his whole self in mystery but has showed us the way and path to reach him.
God has made it clear which path leads to Him- the only path of for sure salvation that won't and doesn't leave us in fear of am I saved or not, or God are you their or not - But he reveals himself to those who seek after him, and yearn to know him and Yes all us can be his chosen people through Jesus Christ- walking in the power of God doing the same works of Jesus- in his name.
We all have a predestined call and job in the kingdom of God if we would just care enough to answer God -who after all is the one who has loved us first- even yet while we were/are still in sin!
Do you know Him? This video is cool >http://www.youtube.com/watch?v=yzqTFNfeDnE