As a Christian, I'm more like an Orthodox Jew than what you probably think of as a "typical" Christian. I preach to everyone about Christ because I want them to have the same happiness that He has been so kind to bless me with. What makes you and I similar, what is it that we desire, but you go about it so differently from me? Union with God. Isn't that what you seek? I was once lost too, but Christ sought me. I ran from Him, even after I acknowledged and accepted His truth, trying to believe just about every other religious nonsense that came along. He chased me though, and now nothing can separate us, ever, and I will be with Him in the World to Come. That's what you are looking for, but try and try as you might, you cannot get there on your own. Man cannot get up to heaven; heaven must come down and draw near to him. Jesus brought the Kingdom of Heaven near to man. That's what the bible says.
Now why are there so many different theological opinions and different ways of worship among people who profess to know Christ? I personally think the answer lies in the analogy of the sin of the golden calf. Men, and I mean humankind, cannot leave well enough alone. They constuct concepts,and you will notice, put THEIR names on them and say "This is what you should believe." Or, they build big fancy cathedrals or mega-churches, and begin to worship money, and then they get even more confused. Then it's not about God anymore, but them, and they worship themselves soon enough, and so they bicker among themselves as to who's right, when it was never about all that in the first place.
You might notice that what are called "Christian" churches today have thrown out the Word of God and are just social clubs and entertainment centers: the preacher preaches his own ideas, whatever they are and the entertainers get up and sing a lot.
Anyway, there are still some of us left who skulk around spreading what the Lord so elegantly taught, without all the trappings that man has fashioned. And that is the simple message, that only through Him can you find that ineffable happiness, that you seek, and that is eluding you: trust in Him as your Savior and accept Him, ask Him to come into your heart (all this is done by praying)and you too, can reach that other shore.
Now see, here you are a gentle soul asking perfectly good questions and you get yelled at. Jesus would never yell at you, nor will I.