God the Father
Romans 8: 15For you did not receive a spirit that makes you a slave again to fear, but you received the Spirit of sonship. And by him we cry, "Abba, Father." 16The Spirit himself testifies with our spirit that we are God's children. 17Now if we are children, then we are heirs—heirs of God and co-heirs with Christ, if indeed we share in his sufferings in order that we may also share in his glory.
God the Son
Matthew 26:62Then the high priest stood up and said to Jesus, "Are you not going to answer? What is this testimony that these men are bringing against you?" 63But Jesus remained silent.
The high priest said to him, "I charge you under oath by the living God: Tell us if you are the Christ, the Son of God."
64"Yes, it is as you say," Jesus replied. "But I say to all of you: In the future you will see the Son of Man sitting at the right hand of the Mighty One and coming on the clouds of heaven."
God the Holy Spirit
John 14:15-17: "If you love me you will obey what I command. And I will ask the Father and He will give you another Comforter to be with you forever - the Spirit of Truth. The world cannot accept him because it neither sees him nor knows him. But you know him for he lives with you and will be in you."
For those interested here is a website I found while googling "God the Son." It explains some about the meaning of "son of God" for people who have a hard time thinking of this as anything other than a biological relationship.