Why so many methods of meditation?

I initiated many friends into the practice of Dhammakaya meditation. They asked me why there are so many methods of meditation and why all the traditions claim that their method is the best. I would like to know how I should explain this issue to them.

The Executioner Behead a Prisoner

Before the execution, the primary swordsman drank a large amount of alcohol to calm himself. Just when he was about to make the killing blow, his energy level dropped greatly until he was unable to sever the prisoner’s neck immediately. The primary swordsman lost his footing because he struck his blow at the wrong moment. So he ended up obstructing the path of the second swordsman who was raising his sword to administer a follow-up blow.

We Have Each Other

Story of a teacher whose husband’s father is drunken and flirtatious and ended up broke. Her brother had hepatitis but he recovered and stayed longer for a certain time because of the merits. What Karma causes rheumatism sickness? Does it have any effect if one is upset while accruing merits?