How do you know who the guardian of your soul is from the spirit world?

Good question. Your spiritual guardian may or may not be revealed to you during your life. If they are revealed to you then they will use a medium to make contact with you. The medium will identify the characteristics and description of who they see is your guardian and note you may have more than one. You will think about this and in most cases your own guardian will be a passed over loved one, such as a grandparent or great-grandparent. During your spiritual path in life you may then have other mediums or even yourself pick up things in your own psyche that confirms the same guardian is around you. So you then conclude that they are all describing the same person they see and then you conclude this person must be my own spiritual guardian. But please do not search for your own guardian, they are there and they will make their own presence known to you if needed.