You can find the answer in orthodox prayers like this one:
Oh Good Father, and the Most Holy Son and the Holy Spirit, Oh Most Holy Trinity, Oh God undivided, save me, the sinner.
In the Orthodox confession of faith (creed)
I believe in one God, the Father allmighty,..and in One Lord, Jesus Christ, ..consubstancial with the Father by whom everything was made...and in the Holy Spirit..which proceeds from the Father, and who with the Father and the Son is worshipped...
In the bible:
Whomever has seen the Son, has seen the Father, and whomever denies the Son, denies the Father too.
And in the teachings of some Saints:
"Today we celebrate in the honor of the Father, and the Son and the Holy Spirit – one God in three Persons" St John of Kronstadt, opening words of one of his sermons in the day of Pentecost.
Jesus Christ is our God, the One and only God.