Romans 8:15-16 AMPC
For [the Spirit which] you have now received [is] not a spirit of slavery to put you once more in bondage to fear, but you have received the Spirit of adoption [the Spirit producing sonship] in [the bliss of] which we cry, Abba (Father)! Father!
The Spirit Himself [thus] testifies together with our own spirit, [assuring us] that we are children of God.
AMPC: Amplified Bible, Classic Edition