The generally accepting timeline division is a result of the impact of Christianity in the world. However, one does not need to believe in Christ to acknowledge the timeline as a system of measurement. Non-Christians do it all the time.
Concerning worship prior to Christ, well not much has changed in the pagan world. In terms of Judiasm, Chrsitianity is simply a fulfillment of the Law and the Prophets. The continuation of you will.
So Jews prior to Christ and Christians worship the same God.