Whoever strives for wisdom (what the OP seems to mean by "enlightenment") should study thoroughly and critically whatever ideas mankind has produced - starting with the ones that were most influential on one's native culture. We can learn from such ideas and their historical and sociological contexts no matter to what extent we approve of them. In other words, we study mankind as such.

Religion is a different thing from wisdom, though somewhat related. There is no such thing as a best, good, bad, or worst religion (as opposed to theology or religious teaching). Your religion is your identity, rooted in the history of your cultural context, so you normally have no choice at all. Rather, some people can be said to have more religion than others.

Religious teachings are attempts to verbalize religion, necessarily inadequate. The larger part of religion is non-verbal, encoded in rituals and everyday customs. For children, the first important question is "Who are we?", then comes "Who am I, and how can I interact with this community?", and only third, and latest, comes "What is the world like?" For each of these questions we have distinct languages - since they use the same words, they sometimes seem to conflict. We must remind ourselves and others from time to time that religion is not meant to tell us anything about the objective world.

Like all aspects of human life, religion is being hijacked to increase some persons' own ego, power, wealth, etc. This means that even the most righteous religious leaders cannot always be trusted to say, or even know, the truth about the very religion they represent. If you asked Bill Gates about the nature of computing and software, you would not expect an unbiased answer either, and you would not condemn all computing because of his unsatisfactory answers.

The relation between religion and doing good is much more complex than reflected in verbal teachings. In particular, it is absolutely wrong to believe that religion was invented to make simple people altruistic and obedient.