You call the man Pastor because everyone else calls the man Pastor.
John is Pastor John, Jack is Pastor Jack and Joe is Pastor Joe because John, Jack and Joe taught you to call them Pastor.
There are practical reasons for calling the man Pastor, but a much more significant reason not to…. the Lord Jesus Christ forbids it. Listen to your Master:
“DO NOT BE CALLED ‘RABBI’; FOR ONE IS YOUR TEACHER, THE CHRIST, AND YOU ARE ALL BRETHREN.
“DO NOT CALL ANYONE ON EARTH YOUR FATHER; FOR ONE IS YOUR FATHER, HE WHO IS IN HEAVEN.
“AND DO NOT BE CALLED TEACHERS; FOR ONE IS YOUR TEACHER, THE CHRIST.”
True, the Lord Jesus does not specifically outlaw calling a man Pastor, but let us reason together….
In these three verses in Matthew 23, various translators use a variety of words expressing what they believe to be forbidden titles: Rabbi, teacher, master, father, instructor, leader, director. The Lord Jesus did not specify Pastor because it was not the custom to call religious leaders by that title. Nonetheless, He said enough for you to ‘get the picture’ if you want to ‘get the picture’.
And if you don’t you won’t.
For those who don’t and won’t, consider: If it were the evangelical practice to call the man Lord would you call the man Lord? And if not, why not? After all, our High Priest did not instruct us, “DO NOT CALL ANYONE ON EARTH” Lord.
If you call Whoever Pastor Whoever simply because everyone else does, and even occasionally refer to him as Reverend, you would surely call him Lord Whoever if that were the custom.
No way!, you say. Jesus is my only Lord, and I would never call any man Lord!
Really? How many shepherds do you have (pastor, as you know, means shepherd)? And yet you call several men Shepherd, an insult to the good Shepherd who proved His love at Calvary.
You have one pastor; His name is Jesus.