This is Kate's jacket. = This jacket belongs to Kate.
That's our neighbors' dog. = That dog belongs to our neighbors.
Belong with means that things/people are similar and should be together. If one person in a romantic relationship says "You belong with me," it is like saying that it is destiny for the two people to be together.
You can also use belong with or belong in for putting an object into a category with other, similar objects:
That book about humans traveling to Mars doesn't belong in the history section. It belongs with the other science fiction books.
An object belongs IN a category, and belongs WITH other similar things.
There are quite a few other benefits that people have found to be useful in a cup of blackberry tea. Evidence suggests that drinking blackberry tea may be able to help support the digestive system and the many antioxidants present in this tea also make it good for preventing freeradicals from damaging healthy cells. Regular consumption of blackberry tea has been noted to help support focus and memory.