Keep away

Yesterday Buddy had an adventure that turned into a lesson for me too.
We were on our morning walk to the neighborhood park. Buddy thinks it is his park, exclusively. He has this tiny problem , he is anti- social while on the leash( called leash aggression by trainers).
Yesterday when we entered the park, I saw an older man on the other side of the hill. The park is situated in such a way that the center is a plateau that slopes down on each side. I could not tell if this man had a dog, but did not see anyindication, so relaxed. All of a sudden, this very friendly Lab came running to play with Buddy. He immediately he began yelling( I think):
'Get back. This is my park and my person. You do not belong here. Get back from us and you will not get hurt.'
As an aside, I often wonder if he is protecting me or himself?
The dog continued running toward us and Buddy went into his full attack mode. Finally the dog stopped , stared, then turned, and ran off, for which I was thankful.
A younger man appeared to see if the older gentleman was OK since he heard Buddy yelling. It probably sounded like a dog fight. I assured him that all was well and he headed back inside.
On the walk home I thought about how I need to treat Satan with his temptations that way. Not entertain him, or let him get close to me. I need to yell and say:
Get away from me. I belong to Jesus and you have not right here. Get out of my head and stop whispering to me.
I think it was either Augustine or Martin Luther who said
" You can't stop a flock of birds from circling over your heard, but you can keep them from landing in your hair."