There are many good reasons for praying to God, depending on how you perceive God of course. In my experience, the best and most pure reasons are praise and gratitude. Love for God is an upwelling of the soul, and prayer is one way to express it.
I have not found that God will do things for me or give me advice. I know that many people do experience God in that way, and good for them. Clearly I have got a different God or a different relationship with God.
Shamanism works with helping spirits. One way of thinking about these helping spirits is as step down transformers. The Shaman works with power, here meaning a vital force that is more positive than just energy. Helping spirits moderate that power. Too much power is as unworkable as too little. If you think of the Divine as infinite power, helping spirits are almost literal step down transformers.
Helping spirits can be deities. If you are a soft polytheist, those deities can show up in different religions or in pagan pantheons, or as local spirits. Some are more powerful than others, but that does not make them necessarily less amenable. In the Upper World especially, the Shaman is introduced to great figures from different religions as helping spirits.
Shamanism is not a religion or a belief system. It is a practice. It is the practice of working with spirits to effect change, such as healing or divination. The Shaman travels in Non Ordinary Reality to do this. It is a social role for a practical purpose.The spiritual world view behind this is animism. Animism is not a religion. I will explain why I think this.
Animism underlies much of the great religions. It is not a primitive form of those religions or a precursor to them. It is like the substrate. If religion is the carpet, animism is the underlay. It is our oldest spiritual practice and we were animists for 90 percent of our history. You can't say first we had animism and then we had religion, because animism is still there underneath the surface. You just don't see the underlay when you walk on the carpet.
Animistic ideas leach into religious ones. All religions are syncretic. The gods of the old faith become the demons of the new. Sometimes they become the saints, or mythical heroes, or local nature spirits. I have written before about the Roman Catholic practice of using holy water to bless an item as if it is animate. Older and more complex forms of religion have animism shot through them like shimmers of light on silk.
Religious ideas leach into animism.Shamanic practice is in part culturally influenced - in Non Ordinary Reality we experience what we are primed to experience, to some extent. I don't believe there is any 'pure' Shamanic experience, but in my culture we read and write and talk so much about everything it would be even more impossible to experience something that was not informed by previous understandings. Shamans work with the helping spirits of their religious cultures. They may identify with a religion and practice Shamanism alongside it, or they may practice something more obviously syncretic.
Modern Christianity in particular emphasizes belief. I am a little careful here because I suspect the original use of the word 'credere' meant something like 'you will understand it best once you have had a go at it'. Modern Christian conversion stories talk about belief as being an overwhelming certainty that does not rely on outside evidence.This is described as exhilarating and sustaining. One's experience is governed by belief. For animists, it seems to be the opposite. There is a very low standard of belief. It really matters little what you believe. What matters is what you experience in relationship. Noting is autochthonous. Experiences beget ideas and experiments in consciousness are looped back into praxis. Useful questions might be 'What does it do for you? How does it help the community? Where does it change you? How can this be supported?'
The idea of persons is helpful in animism. We are human persons, but there are non-human persons, other-than-human persons, and more-than-human persons. The only religions I know anything substantive about are Islam and Christianity (perhaps Judaism by extension). Both religions abound in persons that are not human. In Islam, we share the earth with various Jinns, angels and demons. Christianity gives us saints who may well have been seen as not human originally, as well as the usual angels and demons. Our ancestors are also once-were-human persons who crop up within religious culture even if not in the written canon. Ancestor veneration is important within the religions of Taoism and some Buddhism.
It would not surprise me if the great Manifestations of God, founding religious figures, did Shamanic things. I think of the miraculous Night Journey of the Prophet Muhammad, where in one night he rode a magical horse from Mecca to Jerusalem and then up into the heavens, and in graded levels of NOR he met the previous Prophets. He took this journey at a time of great travail among the new community of Muslims, and while grieving the loss of his wife. On his return, he was able to describe things he could not have seen in Ordinary Reality. This sounds to me like an Upper World journey. I am not saying here that prophets such as Muhammad were just Shamans, only that they did things that seem to be Shamanic.
Animism is not a religion because it is not systematic. It is informal and pluralistic. I was taught by the Foundation for Shamanic Studies that there are three worlds - Upper, Middle and Lower. For many animistic world views this is true, but not always. In Norse animism there are nominally nine worlds, but the relationship among these is expressed differently in different places. From the early modern period onwards, Europeans have loved taxonomies. Putting things in places is an aesthetic joy. But our sense of orderliness falls over when it comes to the many different expressions of animism. The worlds of spirits tumble over each other in an entanglement that just gets bigger and richer the more you explore them. I have experienced the three worlds, but not as a static, discrete system that I can easily describe. As Walt Whitman said
'Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)'
It is a wonder that we can share language about these worlds, but they have enough in common that we can. The worlds of the Shaman are interactive with the Shamanic experience. You roll the carpet out in front of you as you go, while also being aware that thousands of practitioners have also rolled out their carpets.
Further: Nordic Animism YouTube Channel is an interesting take. Thanks to Kevin Turner of FSS for the analogy of the step-down transformer. The Night Journey of Muhammad is attested in many hadith. When you read about it, you will find other examples within religion.