What does the Bible say about changing religion? (Part 1 of 3)

What I understand from Brother Eli's video of which anyone can watch and respond to:
https://3speak.co/watch?v=fatimajunio/urqvbwoj

The term, Sunday School Teacher is not biblical. Teachers are sent by God according to Ephesians 4:11 which says that different positions in the church, including teaching are given by our Lord Jesus Christ.

If one is a teacher, he should be a teacher on all days, not only on a Sunday. 2Tim. 3:7 talks of people who are always learning but, never coming to the knowledge of truth.

A teacher that is elected by Christ should be a teacher on all days, and not only on a Sunday.

The Seventh Day Adventists say the worshipping on Sunday is the mark of the Beast in what is regarded as the Great Controversy. There are man-made teachings in the doctrine of the Seventh Day Adventists.