Sorry for the delayed response.
First, how do we know what we worship is correct? And even further: Does it matter what we worship or is any form of worship sufficent? and even alittle more further: Does it matter how we worship?
People worship all sorts of things: Some God or Gods, some statues or spirits contained or represented by the statues, some money, some other humans, etc.
So it is important to ask: How does one realize they are worshipping the correct "Thing"?
First of all, it is important to realize that often times people on the basis actually are believing/worshipping in the same entity, they simply refer to this entity differently or quite possibly have a different understanding of the entity. For instance, in some religions Native American religions a "Great Spirit" or the sorts of is spoken of. I understand this "Great Spirit" to be in some regard equilivent to God, however I'm sure the understanding of the two varies. But why are there so many conflicting views of what or who the creator of the universe is? You have beliefs from having a creator who has basically either died or just abandoned us here (Deist), you have people who believe in multiple active Gods (Polytheism), then there is people who believe in one God (Monotheism), and even sortof a mix of polytheism and monotheism where there are many Gods but one is the head God (Henotheism). I personally feel there are two main possiblities to all the variance:
A. (Possible Non-believers persective): God doesn't exist and people are just making things up. So when one person makes his god up, someone somewhere else makes his up, and naturally the two independent people are not going to create the same imaginary friend.
B. (Possible believers persective): God does exist, however there is absolutely no way for God to reveal God's (Sorry about the strange wording, I refuse to use any gender related pronouns or pronouns in general such as He, which is commonly used) essence to us, because of what God is. The only way for a human to understand God is to be God or be Gods. Maybe you can relate it to how men don't always understand the thought process of a woman, but other women can do so better because they are one. So because we are not God or Gods ourselves we can not understand God to a full extent. We can however by analogy and other indirect methods possibly describe God in such a way as not to be entirely wrong, yet not entirely right. When you have a bunch of humans receiving these indirect descriptions of God, then it is bound for people to have alternative interpertations. Not only this but we must consider humans also have the option of corrupting a religion for their own benefit.
So in short: We cannot be certain. Even people with faith are not certain. Faith is in essence what you have when you don't really know!
But the way I see it personally is the following:
Even if we don't know our view of God or our view of the "Divine Creature" is correct, we can still worship what we believe with some assurance. But before we do, we must determine by thought whether God is but one or of many (This is very important). Everything else, including the nature of God, is secondary to actually believing in God in some form. So for instance, although I whole-heartly disagree with the Christian view of God's nature being a Trinity, I wouldn't consider there prayers to be for any other than the God I believe in IF they intend their prayers for God as a whole. I know some people who actually worship Jesus the man (And I believe they simply misunderstood the Trinity.)
Secondly we come to the standard by which revelation should be judged to be true or false. So far no such agreed upon standard has been found, because if it really had been found everyone (I guess sensible people at least) would join the belief in that revelation. I think one difficulty is that everyone who has some religion with the belief in God feels God solely endorses their religion and everyone else is pretty much screwed. Well this notion I find to be nothing short of silly, because if God is Just then we should have a undoubtly instant of proof so that we know what we belief is true before we get punished. It would follow that since God is Just, God must be considerate about the spectrum of beliefs and if God feels the need, correct them in the afterlife. That is why I believe all religions who believe in God were at the very least founded upon a true religon, but have since skewed from it. Some religions I regard as being perfectly fine, even though they don't agree with Islam. So far I see no problem with Judaism and Christianity (And for Christians this is so long as they are truly monotheistic in heart and worship God as a whole and not in part, since Christianity has the Trinity concept of God's Nature). As for other Religions, it is very possible many others are fine as well. Honestly I haven't had the time to research sufficently to conclude one way or the other, since I spend a great deal of my time examing even my own religion and the other two religions highly related to mine.
Peace