"Biblical Christianity" is simply publicly announcing Jesus Christ the Son of Jehovah as your personal Lord and savior.
All other religions teach how to live, enlightenment and other such life lessons but Christianity is the only religion that not only teaches but also proves the resurrection and is given to us as a promise for eternal life which we all hope for. Only Jesus Christ has conquered death and can give this gift.
Therefore we take on the name Christian i.e.. "Christ Like" because of this simple understanding and belief in Jesus and what He has done and can and does in our lives. We are given the opportunity to allow Christ to live in us, this is how we become Christians.