“The nature of the rain is the same but it grows thorns in the marshes and flowers in the garden” – Source: Arab Proverb
You can give the same advice to two people, one will use it wisely and benefit, one will use it foolishly and cause damage. It is not the advice that was at fault but its interpretation and implementation.
This is also a reference to people who want to attain self-awareness but believe they need a guru or saviour to help them achieve it. They can provide the rain but what you do with it is up to you.
One person can read the bible and become peaceful, another can read it and embark on a life of violence against others. Both read the same text but interpreted it in different ways.
This quote also reflects contradictions often made by religions. They attribute positive things that happen to a person (say Jesus) but negative events to people (sinners).
In truth if someone iconic (like Jesus as an example) says something and some people do positive things because of it the praise should be with the people who did those positive people. Others listening to the exact same might do negative things and the responsibility lies with them. The message (and the messenger) take no credit or criticism.