There are several heresies that one needs to be careful of when discussing a topic such as this. For example, Modalism which declares that God is not three distinct persons, but that He merely reveals himself in three different forms. Or, Arianism which declares that Christ and the Holy Spirit are creations of the Father and not one in nature with Him. Or Partialism which declares that the Father, Son, and Holy Spirit are not distinct persons of the Godhead, but are different parts of God each composing 1/3 of the divine.
The only accurate answer one can give is what is confessed in The Athanasian Creed.
The Athanasian Creed
Whoever desires to be saved must, above all, hold the catholic faith.
Whoever does not keep it whole and undefiled will without doubt perish
And the catholic faith is this, that we worship one God in Trinity and
Trinity in Unity, neither confusing the persons nor dividing the
For the Father is one person, the Son is another, and the Holy Spirit
But the Godhead of the Father and of the Son and of the Holy Spirit is
one: the glory equal, the majesty coeternal.
Such as the Father is, such is the Son, and such is the Holy Spirit:
the Father uncreated, the Son uncreated, the Holy Spirit uncreated;
the Father infinite, the Son infinite, the Holy Spirit infinite; the
Father eternal, the Son eternal, the Holy Spirit eternal.
And yet there are not three Eternals, but one Eternal, just as there
are not three Uncreated or three Infinites, but one Uncreated and one
In the same way, the Father is almighty, the Son almighty, the Holy
Spirit almighty; and yet there are not three Almighties, but one
So the Father is God, the Son is God, the Holy Spirit is God;
And yet there are not three Gods, but one God.
So the Father is Lord, the Son is Lord, the Holy Spirit is Lord;
And yet there are not three Lords, but one Lord.
Just as we are compelled by the Christian truth to acknowledge each
distinct person as God and Lord, so also are we prohibited by the
catholic religion to say that there are three Gods or Lords.
The Father is not made nor created nor begotten by anyone.
The Son is neither made nor created, but begotten of the Father alone.
The Holy Spirit is of the Father and of the Son, neither made nor
created nor begotten, but proceeding.
Thus, there is one Father, not three Fathers; one Son, not three Sons;
one Holy Spirit, not three Holy Spirits.
And in this Trinity none is before after another; none is greater or
less than another;
But the whole three persons are coeternal with each other and coequal,
so that in all things, as has been stated above, the Trinity in Unity
and Unity in Trinity is to be worshiped.
Therefore, whoever desires to be saved must think thus about the
But it is also necessary for everlasting salvation that one faithfully
believe the incarnation of our Lord Jesus Christ.
Therefore, it is the right faith that we believe and confess that our
Lord Jesus Christ, the Son of God, is at the same time both God and
He is God, begotten from the substance of the Father before all ages;
and He is man, born from the substance of His mother in this age:
perfect God and perfect man, composed of a rational soul and human
flesh; equal to the Father with respect to His divinity, less than the
Father with respect to His humanity.
Although He is God and man, He is not two, but one Christ: one,
however, not by the conversion of the divinity into flesh, but by the
assumption of the humanity into God; one altogether, not by confusion
of substance, but by unity of person.
For as the rational soul and flesh is one man, so God and man is one
Who suffered for our salvation, descended into hell, rose again the
third day from dead, ascended into heaven, and is seated at the right
hand of the Father, God Almighty, from whence He will come to judge
the living and the dead.
At His coming all people will rise again with their bodies and give an
account concerning their own deeds.
And those who have done good will enter into eternal life, and those
who have done evil into eternal fire.
This is the catholic faith; whoever does not believe it faithfully and
firmly cannot be saved.