Creating statements from a raw text
You may want to read about the task of Relation Extraction. The most common scenario is to extract triplets (entity1, relation, entity2). Usually entity1 and entity2 are given and the list of possible relations is known. Common methods use a classifier, others can be rule-based.

With your example from the sentence "Bob is married to Lisa since 1983." the system can extract (Bob, is_married, Lisa)

A variant is Open Information Extraction which tries to extract relations but with no information specified.

There exist multiple projects on the subject such as DeepDive, IEPY or openie-standalone.

This this presentation or this review give an overview of the task.