Answer: It is proper to the Father to beget the Son₁, and to the Son to be begotten of the Father₂, and to the Holy Ghost to proceed from the Father and the Son from all eternity₃.

1. Hebrews 1:5-6;8
2. John 1:14,18
3. John 15:25; Galatians 4:6

For further study see:

1. First of a series of six lectures on the Mystery of Trinity by Dr. R.C. Sproul: