What is a Christian?

Acts 11:26 And when he had found him, he brought him unto Antioch. And it came to pass, that a whole year they assembled themselves with the church, and taught much people. And the disciples were called Christians first in Antioch.

disciples were first called christians... What is a disciple?

DISCIPLE
A scholar, Mt 10:24. In the New Testament it is applied principally to the followers of Christ; sometimes to those of John the Baptist, Mt 22:16. It is used in a special manner to point out the twelve, Mt 10:1; 11:1; 20:17. A disciple of Christ may now be defined as one who believes his doctrine, rests upon his sacrifice, imbibes his spirit, imitates his example, and lives to do his work. American Tract Society Dictionary

CHRISTIANS
A name given at Antioch to those who believed Jesus to be the Messiah, A. D. 42, Ac 11:American Tract Society Dictionary
26. It seems to have been given to them by the men of Antioch as a term of convenience rather than of ridicule, to designate the new sect more perfectly than any other word could do. They generally called each other "brethren," "the faithful," "saints," "believers;" and were named by the Gentiles, Nazarenes and Galileans. He only is a real Christian who heartily accepts Christ as his teacher, guide, and master, the source of his highest life, strength, and joy, his only Redeemer from sin and hell, his Lord and his God. They who rightly bear Christ's name and partake of his nature, and they only, shall finally share in his glory.

Both terms imply one who follows and adheres to Christ's teachings

 

Anyone who is Christ-like. Look at the Bible and see what Christ is like and that is how a Christian should act.