Should tithing be mandatory? No.
There is no coercion in spirituality. Benefits of spiritual action come only when we act from our own freewill. And the more joyously we give, the greater we are given back to. In most spiritual paths it is commonly believed that giving actually benefits the giver more than the receiver.
This means giving to God, the Infinite Creator, unselfishly, without gaining any benefit for yourself. Giving 10% may at first feel difficult, yet it can help to break our attachment to money, ego, and material items.
All avatars teach the spiritual Law of Karma or the Law of Return: In other words, what we do comes back to us. Another way of saying this is “We will always reap what we sow.”
When we are generous in giving our time and money to worthy causes, we will then find ourselves on the receiving end of Spirit’s infinite abundance.
Just as we breathe in, we must also breathe out. Once we experience the joy of truly giving from our hearts, and not being in lack, then we will always find that it comes back to us.