Saguna Brahman, the ultimate God with attributes can be worshipped in multiple forms. The moment you make God an abstract, formless being it's not something you can relate to. This is particularly a genius of Hinduism - you can retain your Krishna and Shiva but have this higher or better idea of God also.
Swami Sarvapriyananda teaches Chapter 10 Verses 12-15 of the Bhagavad Gita. In this series of talks, Swami Sarvapriyananda unfolds the highest truths of Vedanta through the study of the Bhagavad Gita (The Song of God).