Hard disagree on all points. Of course Christians existed prior to 325, that is where the idea of the trinity comes from. It is why the Nicene creed exists in the first place. The only large groups that do not believe in the Trinity are Mormons, Jehovah’s Witnesses, Unitarians, and Oneness Pentecostals. All of which no other church considers Christian besides themselves. Of all the church teachings this might be the only clear cut definition of Christianity.
Hard disagree on all points. Of course Christians existed prior to 325, that is where the idea of the trinity comes from. It is why the Nicene creed exists in the first place. The only large groups that do not believe in the Trinity are Mormons, Jehovah’s Witnesses, Unitarians, and Oneness Pentecostals. All of which no other church considers Christian besides themselves. Of all the church teachings this might be the only clear cut definition of Christianity.