For you did not receive the spirit of slavery to fall back into fear, but you have
received the Spirit of adoption as sons, by whom we cry, “Abba! Father!”
Romans 8:15 ESV
https://bible.com/bible/59/rom.8.15.ESV
To the Romans Paul says that they cry out, "Abba Father", by the spirit of adoption as sons.
Written proof from scripture, that we call God our Father, and it is by the Holy Spirit that we do.
He is not talking to Jews in Rome, but the Christian Church in Rome.