TimothyH.
You said:
Blasphemy can only be committed against God.
This is posted in the apologetics section so I assume you are asking about this argument in relation to an apologetic.
If I were arguing a point (say with someone who says they affirm the Bible but denies the full Divine nature of Jesus—i. e. a Mormon, or a Jehovah’s Witness), I probably would not use this argument.
They would just retort:
“. . . As you did it to one of the least of these my brethren, you did it to me’ (see MT 25:40), so ANY child of God can be blasphemed.”
Then they would wrongly conclude that 1st Timothy doesn’t support Catholic teaching on the Divine nature of Christ (and they would probably try to erroneously extend this denial to ALL verses that concern Jesus).
They also may bring up CCC 2148 saying: “The prohibition of blasphemy extends to language against Christ’s Church, the saints, and sacred things.”
CCC 2148 Blasphemy is directly opposed to the second commandment. It consists in uttering against God - inwardly or outwardly - words of hatred, reproach, or defiance; in speaking ill of God; in failing in respect toward him in one’s speech; in misusing God’s name. St. James condemns those "who blaspheme that honorable name [of Jesus] by which you are called."78 The prohibition of blasphemy extends to language against Christ’s Church, the saints, and sacred things. It is also blasphemous to make use of God’s name to cover up criminal practices, to reduce peoples to servitude, to torture persons or put them to death. The misuse of God’s name to commit a crime can provoke others to repudiate religion.
Blasphemy is contrary to the respect due God and his holy name. It is in itself a grave sin.79
I think there are other verses that defend the Divine nature of Jesus better although I might use this to shore up other points about the Divine nature of Jesus—but I would not rely on it for apologetics purposes. Just my 2 cents though.
God bless.
Cathoholic