Jesus taught by example.  And over the course of His ministry here on earth, He modeled for the disciples not only the power of prayer…but the necessity for constancy, and steadfastness in the process.  Prayer wasn’t an after thought for Jesus…it was the main thought.  Nor was it the last thing He did after everything else had failed, it was the very first thing.  So after Jesus had ascended into heaven and the disciples were alone and scared, they relied on the discipline of prayer Jesus had shown them to face the uncertain world ahead.   The early Church was devoted to prayer…the Church of today should be as devoted.