Purpose. They have elected to be our guides. These guides are just doing their job as they interact with those of us on Earth. Your core guides are a teacher, protector, healer, joy guide, and master teacher.
Compassion. Some spirits that come to us, have lived lives too. They know how hard it is and they want us to succeed. So, they help us. This is especially true of family members. Once they pass over, they are more accessible. They have more time to help us; because, there is no notion of time on the other side.
Truth. Some spirits are working for God to spread spiritual truth. They know there is a lot of miss-information out there and they are here to dispel the ignorance and bring in more truth. As time goes on, we will continue to learn more and more about the spirit world.
Interest. The earth is interesting. Why else would we go through all the trouble of coming to earth and living a life? Writing a life chart is a unique kind of fun and a challenge. Interesting is definitely the best word to describe life.
Emotion. We need to remember that when spirits come around us, they can feel our emotions. This is why we must raise our vibration to communicate with spirit. They are bringing themselves down to a human level. This is challenging to a spirit. This is actually another reason spirits are interested in earth. They feel so much emotion coming from the earth and they want to change it for the better.