Disclaimer: Everything written here is my opinion. Spirituality and the pursuit of spiritual evolution is very tricky in that there is evidence for almost none of it that could satisfy the idea of "scientific fact". Because of this, please use your own judgment and take what you see with a grain of salt, both in this article and elsewhere.
To supply your magic, meditative practice, energy work, or psychic development with the power it needs to succeed, you can choose a god or deity to bond with in order to be connected to the power of that being. We are all capable of building up our own power of course, however, why start from scratch when tools are readily available to make your life easier? That isn't to say that this practice makes spiritual empowerment a walk in the park - no, you still need to do the work yourself.
Energy exists all around us. We ourselves, are energy. Your consciousness is energy. In fact, all energy has a degree of consciousness. You are special because you have a soul - your soul is energy which is self-conscious. Self consciousness is unique. Through your self consciousness, you can direct the rest of the conscious energy. But there are limits - you are currently attuned to a physical body. This limits your options. While normally the energy of your being could fluctuate between the levels of reality to find or create what it needs spiritually, right now you are anchored around the physical level of reality. And you do not have the power to manifest your reality without first drawing it from the higher realms of the spirit realm. And doing this requires a spiritual connection from your soul to the spirit world, which is hard to create when the primary bond you have while alive is to your own physical body and thus to the physical world. Generating power while in this state to be used for spiritual purposes can be quite difficult. That is why there are a few little things that can give you a much needed boost. This is especially important if you want to manifest changes in your life or if you want to develop psychic abilities that you want to either strengthen or unlock.
Bonding with a god's energy helps to provide this boost. And keep in mind, any time you connect with something spiritual *outside of yourself*, you are growing and expanding your own consciousness, it causes you to grow, and you benefit from it. You can become more spiritually aware and powerful because of this alone, but you have the added benefit of connecting to a being who is much more powerful than you. When you do this, and you start to meld with the energy of a god, your own energy will start to shift. You will start to get closer and closer with the energy, and power, of the god that you are bonding with. Eventually, this results in an abundance of positive energy in your life, positive physical changes which result from it, and spiritual growth for you. If you needed something to happen in your life, you may see a door open to allow you to start pursuing it. If you needed to gain a psychic ability, you may start to feel it becoming evident, stronger and 'real'. If you have a lot of bad things happening around you, you may gain a way out. If you lack understanding or direction, you may find it. If you feel alone, you may find someone to support you. There are a lot of good things that can happen due to connecting with a powerful, positive being. As always with these things, to make a worthwhile bond like this happen you must be the one to pursue it.
Speaking of, there are a variety of ways to bond with an entity, but I find that many ways actually distract you from the real purpose of doing so. If what you are doing causes you to focus more on symbolic acts than on the entity itself, then you may not get very far. Ideally you want to do something that will evoke the energy of the god (don't worry, you don't need the god to actually come to you, all you need is to draw on the god's spirit and to focus it into your soul, your mind, etc.) The way I do this is by first focusing the name of the god on the very edge of my awareness, away from physical senses or physical 'mind' - but in a part of my mind that is further from my physicality. This allows me to get a stronger grip on my spiritual will. It is there that I think first of the entities name, I hold it there with the intent to feel that entity, and when I start to perceive a new sensation coming into me from where I am focusing, I then switch to focusing less on the name itself and more of the feeling of the entity that I am connecting with. From here I like to couple my focus with a visualization. I visualize a lantern, the stronger I feel energy come in from the god, the brighter I visualize the lantern being. When the lantern is very bright, I hold that visual and focus on the entity so that I don't lose the connection. When I decide to finish I only do so when I have maintained a strong connection.
The entity that I have chosen to bond with is Lucifer. His energy is beautiful and strong. He is not evil or malevolent. But the god that you choose to bond with is up to you. Many gods from mythology do link to real entities. And many entities have multiple names, given to them by different cultures around the world. Two different mythological gods may in fact be the same entity. Test your bond to a few that you like and see which feels the best to you. Some may be harder to connect to than others, and some may not feel as 'right' for you as others. When you find the right one you will be happy with it.
I hope this information helps, good luck in your practice. Feel free to share if you decide to try this, or what your experiences are with it.