Read: Matthew 1:18-25
But as he considered these things, behold, an angel of the Lord appeared to him in a dream, saying, "Joseph, son of David, do not fear to take Mary as your wife, for that which is conceived in her is from the Holy Spirit. (Matthew 1:20 ESV)
Joseph, was cast into a difficult role in life. He chose for himself a virtuous and righteous young woman to take as his bride, betrothed her, and in the intervening time between betrothal and marriage discovered that she was pregnant. He did what many of us would do in that scenario, he made some assumptions, and not wrongly so. In fact, he showed a lot of character and compassion in his reaction to those assumptions. However, God's plan was superior to Joseph's assumptions and he communicated the truth of the immaculate conception and the destiny of the child with the young carpenter in a dream.
What kind of assumptions do we make? Aren't assumptions really just another kind of pride? Aren't they based on the self-perception that we are right about an issue?
Even in his conception Christ challenged the understood assumptions of the natural order. He challenged Joseph, Mary, and their family. He challenged their communities and friends. And he has never stopped challenging the assumptions we all make on any given day.