I have been a negative influence on those around me at various points in my life. When I was younger, I thought that I knew everything.
I rarely respected any authority, felt the rules did not apply to me, and essentially wanted to rebel against anything. As a result, the company that I kept were people that thought similarly and if they initially didn't, if we kept spending time together, we would start to change one another.
Luckily, I met a woman, my wife, that snapped me back to reality, saving my life.
We are all products of our environment. If we surround ourselves with negative influences, sinners, and deceit, we will be affected by it.
It happened to me, and this Psalms makes it clear the differences that positive and negative influences can have on a person, especially on their relationship to God.
However, surrounded by encouragement, love and understanding, the same individual may flourish and nurture not only themselves but also those around them. Take the disciples as an example: Christ was like a fruitful and healthy tree, and his disciples flourished being near him, and they too, became trees for those around them.
This psalms reminds us to be virtuous, like a healthy tree, in order to avoid transgressions.

