The simplest explanation is in placing the "call no man father" in its historical context as well as literal context. Since Christ is talking about calling men masters and teachers as well as fathers, He is referring to the honorifics given various rabbis of His time, who had devoted followers. They had cadres of followers that belonged to "houses" and the rabbi would be called a "father" of that "house". The warning is then not to follow sectarian teachers, like we sometime do our parents, blindly, to the point that the unity of faith is fractured.