Here is a schematic reflecting how different religions around the world might have impacted on each other. 

• Some have grown out of and/or imported ideas or practices from earlier religions.
  • Sometimes the sharing has been intentional (Christianity, Islam, Sikhism).
  • Sometimes the influence has been secondary due simply to crossing paths through the spread of religions over time. (Taoism & Buddhism, Buddhist influence on Shinto, Zoroastrian influence on Judaism)
  • Sometimes the sharing has been mutual, other times one religion has had more impact on the other than vice versa.
• Sometimes two religions existing in the the same time and place have been in tension with each other, 
  • Some have specifically rejected ideas from the other as they both develop side by side. (Taoism and Confucianism) 
  • Others have been rejected by later religions. (Judaism rejecting Mesopotamian polytheism, Islam rejecting Zoroastrianism, Buddhism rejecting some aspects of both Hinduism and Jainism, even while being influenced by other aspects of the two earlier religions)
  • Sometimes newer religions were rejected by the older ones they grew out of. (Judaism rejecting Christianity, Islam rejecting Baha'i)

Schematic created at Bubble.us

Color code:

• Orange: ancient (often long dead) religions (the oldest)
• Yellow: religions that developed in the Near East/Mediterranean region
• Green: religions that developed in India
• Blue: religions that developed in China
• Purple: religions that developed in Japan

Connections: 

• Sikhism is the link between India and the Near East
• Buddhism is the link between India and the Far East