Everyone who subscribes to a particular religion believes it to be the correct one, by definition. You can provide an infinite number of reasons why it is the 'right one', just like everyone else can, about their religion.
If you find someone that is 'lost', without a religion, you may help that person 'see the light'. However, trying to convince a devout believer of something else is ludicrious, and absolutely offensive.
Saying that your religion is the 'right one' implies that you don't understand why people would choose other religions. If you can grasp this concept, a tenet of religious freedom, it would go a long way toward promoting religious tolerance.
Whether one believes in a religion or not...there isn't anyone who doesn't appreciate kindness and compassion.
- Dalhi Lama