Who is Jesus' father?
Now the birth of Jesus Christ was as follows: After His mother Mary was betrothed to Joseph, before they came together, she was found with child of the Holy Spirit.
(Matthew 1:18)
But while he thought about these things, behold, an angel of the Lord appeared to him in a dream, saying, “Joseph, son of David, do not be afraid to take to you Mary your wife, for that which is conceived in her is of the Holy Spirit.
(Matthew 1:20)
The Holy Spirit is defined in scripture as God's power.
And the angel answered and said to her, "The Holy Spirit will come upon you, and the power of the Highest will overshadow you..." (Luke 1:35)
But you shall receive power when the Holy Spirit has come upon you... (Acts 1:8)