The doctrine of the Trinity is often misunderstood or misrepresented. This was the case with Ahmed Deedat who says in the below video that Christians believe in “one person” (0:49-0:53). That’s not true. By saying this, it is evident that Ahmed Deedat does not understand Christian doctrine (see Matthew 12:36). Historic, orthodox, and biblical Christianity believes there are three Persons in the Trinity.
For more on the Trinity see “Monotheism and the Trinity”