The word Christian is a noun, not an adjective.
It appears three times in the bible and refers to
a person or persons.  We err when we use the
word to describe something else (adjective); such as
a christian school, a christian family, or a christian life.
More correctly would be a school where Christians attend,
A family of Christians, or the life of a Christian.  Christians
are disciples of Christ.  A school is not a Christian.

The passages where Christian appears are:
Acts 11:26  The disciples were first called Christians at Antioch. 
Acts 26:28.     You will soon persuade me to become a Christian. 
I Peter 4:16  suffer as a Christian.
Counterfeit Christians
Lydia, the seller of purple was a counterfeit Christian before
she obeyed the gospel.   She looked and acted like a Christian but was not a Christian until she did what she
was supposed to do in order to become a bonfied Christian.
She was a worshipper of God Acts 16:14 which by appearance would cause others to think of her as a Christian.  Not so! she was a counterfeit christian until she obeyed the gospel.  She became a Christian after she was
baptized at Acts 16:15.
Cornelius, a centurion of the Italian cohort was a
counterfiet Christian
before he obeyed the gospel.
When viewing his lifestyle, one would be quite certain he was a Christian.  A devout man, one that feared God, gave much alms and prayed to God always.  Acts 10:1 and 2.  But he was not a Christian.
Not yet.  He had words to hear and actions to take
before he bacame a Christian no matter how devout
and sincere he was.  If he had already been a Christian, why did he have to hear words by which he and his houshold would be saved?  At Acts 11:14 he remembered the  words telling him what to do to become a Christian.  He did just that at Acts 10:48.
He was baptized in the name of the Lord.  He and Lydia above were baptized to get rid of sins as did the apostle Paul at Acts 22:16.  Baptism washes sins away.  Can you refer to any other scripture that show
you another way to wash your sins away?