Beliefs are a state of mind where we believe something is true, even if we are not 100% sure that we can prove it. Everyone has beliefs about life and the world in which they live. Beliefs that mutually support each other are a belief system that can be religious, philosophical, or ideological.
Religions are belief systems that link humanity to spirituality. The following definition from Wikipedia gives a good overview of the many dimensions of religion:
Religion is a collection of cultural systems, belief systems and worldviews that connect humanity with spirituality and sometimes with moral values. In many religions, there are oral legends, symbols, traditions and sacred texts that are designed to give meaning to life or explain the origin of life or the universe. Typically, morality, ethics, religious laws or a preferred lifestyle are based on the ideas of religions about the cosmos and human nature. […] Many religions contain a certain code of conduct, the presence of worshipers, as well as a definition of the content of participation or membership in a religious community, the life of parishioners; there are regular gatherings or services for the purpose of worshiping a deity or for prayer, sacred sites (either natural or architectural) and / or sacred texts. Religious practice may also include preaching, praising the acts of God or gods, sacrifices, festivals, holidays, trance states, initiations, funeral services, marriage services, meditation, music, art, dance, public services, and other forms of human culture. However, there are examples of such religions in which some or many of these aspects of structure, belief or practice are missing.

All religions, arts and sciences are branches of the same tree. All these aspirations are aimed at ennobling a person’s life, raising him from the sphere of simple physical existence and leading to freedom. – Albert Einstein

Belief in the spiritual dimension of life has existed since time immemorial. Many human societies have left us with evidence of their belief system, be it the worship of the Sun, gods and goddesses, the knowledge of good and evil, or the concept of the sacred. Stonehenge, Bamiyan Buddhas, Almudena Cathedral in Madrid, Uluru in Alice Springs, Bahai Gardens in Haifa, Fujiyama, the sacred mountain of Japan, the Kaaba in Saudi Arabia or the Golden Temple in Amritsar – they all embody the human experience of spirituality, reflect both objective reality and and the result of man’s striving to explain the meaning of life and our role in the world.
In its simplest sense, religion describes “a person’s relationship to what he considers sacred, holy, spiritual, or divine.” This is usually accompanied by some form of organized practice that brings together communities of people who share this faith. As stated above, belief is a broader term that also includes “views that deny the dimensions of existence outside of this world.”

Religions and other forms of belief in our environment affect our identity, whether we consider ourselves religious or spiritual or not. At the same time, other aspects of our identity, our history, our approach to other religions and groups that are viewed as “different” will influence how we ourselves interpret that religion or belief system.