It all revolves around an Ultimate Reality that has attributes. The attributes of this Ultimate Reality are taught by all religions to have commonality. The All- Knowing, the All-Merciful, the All-Forgiving, the All-Comforting, the All-Loving, the All-Wise, the All-Compassionate, among other attributes.
Now, it is also taught in all religions that we possess these attributes within us in various measures.
That's the higher principle in essence.
How that principle manifests in action is where the differences arise between religions, but it is a cultural distortion that results in these differences, not a universal difference.
Here is an excellent, brilliant paper (I think so anyway) that explores this higher principle and its intricacies:
https://bahai-library.com/momen_god_bahaullahKam
