A soul tie in the Christian religion is when two souls become tied together in a spiritual way. Some of the ways that two souls can become tied together include sexual intercourse, close relationships, vows, commitments and agreements.
The Bible does not mention the term "soul tie" in the text. Instead, the Bible talks about two souls becoming one flesh. Soul ties can exist between a married couple, between an abuser and a victim, or between two demonic souls. The reasons for creating soul ties is to draw the two parties closer to each other. Soul ties can be broken in a number of ways which include committing sin together and renouncing the soul tie.