The author analyzes the two most common synonymous Greek prepositions ἐν and εἰς in the texts of the New Testament. She begins with a description of the basic syntactic functions of Greek prepositions, then goes on to analyze the status of two selected prepositions, pointing to the differences in their meaning and their dependence on the connectivity with specific noun cases. The last part of the text is devoted to the pre-verbal value of the prepositions under the study and the compound verbs based on them, which are combined with the verbs without prefixes, which are their basis. This starting point allows conclusions of a syntactic-semantic nature based on the use of the studied forms in the Greek New Testament texts.