In Vaishnavism, Maha Vishnu is the Supreme God. In Shaktism, Goddess Shakti is the supreme being. In Shaivism, Lord Shiva is the supreme being. However, on Smartism, all deities are considered to be the reflection of one God. Hence, it is up to the devotee in Smartism, who they want to follow or worship as the supreme being.
In Buddhism, the devotees want to achieve Nirvana through the path created by their God, Lord Buddha. However, unlike Hinduism, there isn’t a concept of personal God. According to Buddhism, nothing in this world is permanent or fixed, as everything is temporary, and change can occur anytime.