One of the ten commandments is to not envy (desire) that which belongs to someone else. How can a person prevent himself from falling into this trap of desiring that which belongs to someone else? Obviously this is rooted in the fact that we don't fully believe with our entire hearts' that everything we have is exactly what we need and if we don't have it, it means it isn't good for us.

But an interesting way to look at this I heard in the name of the Bnei Yisschar-

We may have at some point in our lives, desired the car that our friend or neighbor has, maybe their house, or possibly their seemingly blissful marriage or wonderful kids. But have we ever desired to have four legs like a horse? Have we ever desired to have wings like a bird? Of course we haven't desired these attributes because it is very clear that these belong to an animal and not a person. As much as it might help us run faster or travel cheaper : ) we want to be a human. We need to take the same perspective when it comes to things that we don't have and others have. We shouldn't want those things because they are simply outside of our being, everything we are supposed to have Hashem provides for us.

May we all be saved from unhealthy envy and desire, rejoicing fully in the lot which we were given.

Shabbat Shalom,

Heath