Matthew 12:50 For whoever does the will of My Father in heaven is My brother and sister and mother.
He being the first born son among us.
Romans 8:29 For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren.
For we are all sons of God through faith in Christ Jesus as many of us were baptized through Him. Giving us the authority to call our brethren "brother" as Peter called Paul.
The reason why we are commanded not to call anyone father for we are all brethren.
2 Peter 3:15 and consider that the longsuffering of our Lord is salvation—as also our beloved brother Paul, according to the wisdom given to him, has written to you,
Though in a relationship, even in a brotherhood, there must be hierarchy - a symbol of authority.
Matthew 23:8-9 But you, 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.
Any reaction to whom most people called "most holy father" or "reverend father"?
Matthew 23:11-12 But he who is greatest among you shall be your servant. And whoever exalts himself will be humbled, and he who humbles himself will be exalted.