Question

what is difference between furthermore, moreover, additionally in addition

Answer 1

First, the similarity is that all the four are connectors which show the sequence of ideas and events. Actually, all the four conjunctions you have mentioned are the ones that work as appendages, i.e. adding same point or idea. For example, look at the following sentences

1. Mr. Nicholson never believed in the supernatural. Moreover, he had a complete faith that as long as he had the Bible, no evil spirit could trouble him.

2. Furthermore, his adventurous spirit could not resist the challenge to sleep in that guest house of the Circuit House in that small valley. 

3. In addition, he had this illogical belief that he can stand against any evil spirit if they ever existed. 

4. Additionally, he had a licensed gun, in case there was anyone that was playing up as a ghost.