"my child",

your wife calls your child "my child",

the same child, 

I can refer the same child as

"Ao-Hui-Ge's child" or

"Ao-Hui-Sao's child" or

"Ao-Hui-Ge'" and "Ao-Hui-Sao'"s child" or

"Ao-Hui"s'child.

the same child.

Likewise,

when we say,

God's Holy Spirit

that exactly means Jesus Christ's Holy Spirit,

because there is only ONE the Holy Spirit,

these expressions reflected the relationship

among three persons of the only One True God.

We can only say that Jesus Christ is God Father's only begotten Son,

We can never say that Jesus Christ is the Holy Spirit's only begotten Son,