When surgeons go into an operating room they scrub vigorously and wear sterilized gloves. It is the closest they can come to being holy.
Holy means without sin, but it also includes being perfectly righteous. It is like a surgeon’s instruments—they are perfectly clean and have absolutely no germs. Now, that is what it took for Mary of Nazareth to conceive the Son of God in her womb while she was still a virgin. It took a sterile process where everything was perfectly righteous and where there was absolutely no sin.
When explaining the process to Mary, the angel Gabriel said to her in Luke 1:35, “The Holy Spirit will come upon you, and the power of the Highest will overshadow you; therefore, also, that Holy One who is to be born will be called the Son of God.” The Spirit of God is said to be holy and He was the divine surgeon that was going to perform the process.
The word holy is a word that means sacred. When used of something physical it means pure and when it is used of a moral situation it means blameless.
Well, the child that Mary was going to conceive in her womb was the Son of God and Gabriel referred to Him as holy. In other words, the developing fetus would be holy, perfectly righteous, and totally without sin. Therefore, the process had to be holy as well, which is why Gabriel said “The Holy Spirit will come upon you.” It was the Holy Spirit who caused Mary to conceive the holy Son of God.
Now you know the real meaning of the word.
Hey, Jesus had to be sinless to be our saviour, which is why He had to be the holy Son of God.