I am an agnostic, while being a believer at the same time.
It does not matter whether God exists or not, but it is good to believe in a higher force.
Belief in a higher force helps us to anchor ourselves to something beyond. Any anchor that rests on the reality that we experience around us will be unstable, for the reality that we experience is transitory.
All life is transitory. So is the Earth, so is the Cosmos. Another illusory reality called time sweeps everything into its bosom, into oblivion.
All this is very scary to contemplate. When you are in a ship being tossed around by the waves of the ocean, it is good to believe that there a shore.
The Abrahamic Religions stop there. After this life, there is no other. You await the day of judgement. Which, if you think about it, is very very scary. There is no hope of redemption or making up, once you are dead. You just wait in limbo , for Allah or the father of Jesus, to judge you and cast you into heaven or hell for eternity. Both are difficult to contemplate, for while Hell can be terrifying, eternity in heaven is too boring. How long can you keep strumming a harp and float around on clouds?
Hindu philosophy went much beyond that, beyond the concept of a single life, into multiple lives, each leading to the other, based on our past actions. You can be elevated to a God, and you can fall back into an inferior life, it all depends on you. The way to escape this cycle of rebirths has also been laid out. This template somehow feels fair and just. You are not judged once and confined to your fate forever.
You can believe in all the above, karma, reincarnation, the works, and yet Hindu philosophy allows for not believing in God.
After all, what is God but a personification of the Higher Force?
Hinduism, while being infinitely more sophisticated in its philosophy, compared to any other philosophical or religious system on earth, also allows for multiple Gods, while postulating that there is only ONE ultimate reality. It seems paradoxical, but it isn't. The mountain is one, the top of the mountain is the destination, but the paths are many.
Depending on where you are, on your starting point, you choose your God, and your path. Since each of us differs in our state of evolution, each of us is at a different starting point.
Hence, I believe in Sanatana Dharma, the deepest and most profound, most irrefutable philosophical system ever conceived.
And I can be a staunch believer in Sanatana Dharma, while being a theist, an atheist, or an agnostic. It does not matter.