Jesus was simply exposing the inappropriateness of the behavior of the scribes and Pharisees who desired to be honored publicly. Perhaps their top three favored forms of being addressed in public in those days were:
In Jesus' estimation and economy no one but God is as worthy of any of those appellations. That's not to say we must not call anyone "teacher," "father," or "leader." It is to say we as Christ's followers should not play into the hands of those people who want only to be noticed, recognized, and the center of attention as they perform what they consider to be God's work, whether teaching, mentoring, or leading.
If a true brother or sister in Christ is a teacher, mentor (father or mother), or leader, he or she should go about his or her business in teaching in the same way any other brother or sister in Christ might go about his or her business in helping, giving, exhorting, showing mercy, prophesying, pastoring, administering, leading, mentoring, or whatever the spiritual gift.
The greatest teachers, mentors, and leaders will not draw attention to themselves but will be satisfied being humble servants in the employ of the King of kings. From their point of view, if God chooses to exalt them at some point in their ministry, fine; if not, then that's fine, too. After all, we all are at best, servants of the King (see 1 Corinthians 3:5; 4:1).
We may be rewarded for faithfulness in this life, but then again we may not be. We will, however, be rewarded in heaven. From my perspective, my Lord's words
"Well done, good and faithful servant"
will be a sufficient reward for me! (See Matthew 25:21 and 23.) As for the scribes and Pharisees Jesus criticized, their reward began and ended in this life, with no possibility of a future reward. In this regard, what did Jesus say about their reward for public almsgiving, prayer, and fasting as recorded in His Sermon on the Mount?
"'Beware of practicing your righteousness before men to be noticed by them; otherwise you have no reward with your Father who is in heaven . . . Truly I say to you, they [viz. the hypocrites who parade their righteousness] have their reward in full'" (Matthew 6:2, 5, and 16).
In conclusion, there is nothing wrong, I feel, in addressing a teacher, a mentor, or a leader in a respectful way, as long as said person is not on an "ego trip" as were the scribes and Pharisees Jesus described in Matthew 23. For a man to be called "my spiritual father or mother," his or her motive in wanting to be addressed as such must not be rooted in pride and the desire for attention and notoriety.
In the U.S., for example, we might address someone as "Doctor" (Ph.D or M.D.), "Boss" (or "Sir" or "Ma'am"), or "Pastor" (or "Reverend" or "Bishop" or even "Father," within the Roman Catholic Church) and not thereby incur Jesus' wrath. Again, if the said person considers himself or herself a servant-leader, teacher, or mentor, and is humble in that role (or "gifting"), an honorific title is perfectly OK. What does the Scripture say?
"Render to all what is due them: tax to whom tax is due; custom to whom custom ; fear to whom fear ; honor to whom honor" (Romans 13:7 NAS, my emphasis).
Does it go without saying that for a child to call his dad "Father" is also perfectly acceptable to God? Again, our earthly dads and moms are those to whom honor is due!