I have a slight confusion, I know that Jesus is GOD in human form, but I read a passage (can't remember right now) where it read something along the lines that then Jesus rose on the third day and sat next to GOD his Father in Heaven.

My question then is: Is Jesus GOD or is he the Son of GOD?

What Marsha said. Jesus Christ is both God and the Son of God.

This may help you understand the Holy Trinity better:

http://www.newadvent.org/cathen/15047a.htm

My question then is: Is Jesus GOD or is he the Son of GOD?

Our Lord Jesus is God, the Second Person of the Blessed Trinity, the sole-begotten Son of the Eternal Father, with Whom, together with the Lord Holy Ghost (Who proceeds from both the Father and the Son), lives and reigns as God; Who, on account of the infinite love He cherished for the human race and the ineffable zeal wherewith He was all jealousy for the sanctity and majesty of His Father, outraged by the sins of mankind, became incarnate by operation of the Holy Ghost in the immaculate womb of the Blessed Virgin Mary, assuming a human nature in order to redeem fallen man; so that He is perfect God and perfect Man, having His Eternal Father in Heaven from whence He is eternally begotten and yet with Whom He is ever co-equal and co-substantial, and having a Virgin Mother upon the earth from whose all-pure, all-holy flesh (preserved from all sin from the moment of her Immaculate Conception) He assumed our nature and forever united Himself thereto.

The union between the divine and human natures of Our Lord into one Divine Person in the redemptive Incarnation is known as the hypostatic union.

The whole of Sacred Scripture and holy Tradition testifies to this central dogma of the Catholic faith.

When the Evangelist records that Our Lord ascended unto Heaven and sat at the right hand of the Eternal Father, one should interpret it as meaning that the Incarnate Word has the plenitude of authority and power, even as Man, that is co-equal unto the Eternal Father. This sovereignty shall be exercised in its terrifyingly wondrous fullness before the whole of mankind at the General Judgment.

This is an important question because the prayerful consideration of these truths is what imbues with significance and spiritual vitality Advent and the whole of the ecclesiastical year for the interior soul.

God alone, says St.Thomas Aquinas, is pure act, and unlike in all creatures there is no admixture of potentiality in Him. There is nothing that He might become that He is not. Both His intellect and His will, therefore, unlike as in creatures who have both actuality and potentiality, are so related to Him as to be the divine essence itself, for if it were otherwise, there would be potentiality in God, which is impossible for a Being who is the First Cause of all things and whose existence is therefore His essence.

This is also the doctrine of the Fathers on the true interpretation of the passage of Holy Writ, that the Word was with God and the Word was God. The Word of God, which evidently refers to His intellect and act of understanding, is so generated from the Father as to be His very essence. So the word of God is His very essence, and contra the heretic Sabellius, there is a true distinction between Father and the Son, which is a distinction of person but not of essence.

Likewise, in God, His will is His essence. Now, the will of God proceeds in an eternal procession of love between the Father and the Son.

And likewise this is the the interpretation of Our Lord's high priestly prayer "the love wherewith thou hast loved Me, may be in them" which refers to a prayer that the person of the Holy Ghost may be in His Apostles and also that this person is eternal for "thou hast loved Me before the creation of the world", and this person is the divine essence, as the same Apostle who recorded this prayer also writes "For God is love".

Thus St.Thomas says,

"Hence as His essence itself is also His intelligible species, it necessarily follows that His act of understanding must be His essence and His existence ... And as His intellect is His own existence, so is His will."

In speaking with the Apostles, the Fathers, the Doctors, the Saints and the theologians of so lofty a subject as God Almighty and His very nature and essence itself, one must speak with trepidation and maintain absolute precision, for otherwise it is easy for us to fall into error, in the most vital matter, as liturgical tradition even has handed down, the distinction of persons and the unity of essence.

There is no distinction at all in the Holy Trinity in terms of essence, there is one and only essence, the only distinction is that between "Him who begot" and "Him who is begotten" and likewise of "Him who proceeds" i.e. only a distinction of persons arising from relation but all and each person is the divine essence, so that it is true to say God is begotten of God and God proceeds from God, we may thus truly say, that each person is the one God, that is, that the Father is God, the Son is God, the Holy Spirit is God, and they are one God.