Dilemma caused by differing viewpoints regarding soul and karma
A concrete, substantial self implies inherent existence. Inherent existence is the lens of delusion through which we naturally view the world. Buddhism teaches dependent origination, which helps free you from this root delusion. 

To believe in the Hindu scriptures, you have to rely on faith. Buddhism's principles become self-evident through honest introspection, not faith.

The purpose of meditation is to free beings from suffering, at least from a Mahayana Buddhist perspective. If you are still clinging to cyclical existence, this ultimate end seems impossible as you are still heavily under the spell of the root delusion.