The poem ‘Letter to a Friend’ by Nagarjuna beautifully sets out some basic guidelines for a non-ordained person to live their life.
But even if all these guidelines were followed, there would still be some challenges. A great deal depends on the individual concerned, their karma and other factors. For example, some people may have the motivation, but perhaps lack the circumstances. Others may have the circumstances but perhaps lack the motivation – in terms of entering ordained life, of course. So it is really a hard thing to say how best to lead ‘a normal life’, as everyone is different.
The monastic sangha is crucial to help ensure the Buddha-dharma’s benefit for all sentient beings. Without it, I would say that it would be very, very difficult for the Buddha-dharma to flourish. I believe that this was one of the very first reasons why our historical Buddha Shakyamuni established the sangha. I don’t think he intended to develop the monastic system to convert everyone. But, should an individual, according to their own aspiration, wish to access the Buddha-dharma and follow this path, then the sangha enables them to do that.
So, there are many helpful guidelines for non-monastic life in ‘Letter to a Friend’ by Nagarjuna, though one should always be mindful of the benefits and importance of the sangha