"Whosoever will be saved, before all things, it is necessary that he hold the catholic (i.e., universal, Christian) faith. 

Whoever wants to be saved should above all cling to the catholic faith. 

Which faith except every one do keep whole and undefiled without doubt he shall perish everlastingly. 

Whoever does not guard it whole and inviolable will doubtless perish eternally. 

Now this is the catholic faith:  We worship one God in trinity and the Trinity in unity, neither confusing the persons nor dividing the divine being.

For the Father is one person, the Son is another, and the Spirit is still another.

But the deity of the Father, Son, and Holy Spirit is one, equal in glory, coeternal in majesty.

"Such as the Father is, such is the Son, and such is the Holy Ghost.  The Father uncreate, the Son uncreate, and the Holy Ghost uncreate. 

What the Father is, the Son is, and so in the Holy Spirit.  Uncreated is the Father; uncreated is the Son; uncreated is the Spirit.

The Father incomprehensible, the Son incomprehensible, and the holy Ghost incomprehensible. 

The Father is infinite; the Son is infinite; the Holy Spirit is infinite.

The Father eternal, the Son eternal, and the Holy Ghost eternal.  And yet they are not three Eternals, but one Eternal. 

Eternal is the Father; eternal is the Son; eternal is the Spirit.  And yet there are not three eternal beings, but one who is eternal.

As there are not three Uncreated nor three Incomprehensibles, but one Uncreated and one Incomprehensible, so likewise the Father is almighty, the Son almighty, and the Holy Ghost almighty.  And yet they are not three Almighties, but one Almighty.

As there are not three uncreated and unlimited beings, but one who is uncreated and unlimited.  Almighty is the Father; almighty is the Son; almighty is the Spirit.  And yet there are not three almighty beings but one who is almighty.

So the Father is God, the Son is God, and the Holy Ghost is God.  And yet they are not three Gods, but one God.  So likewise the Father is Lord, the Son Lord, and the Holy Ghost Lord, and yet not three Lords, but one Lord.

Thus the Father is God; the Son is God; and the Holy Spirit is God.  And yet there are not three gods, but one God.  Thus the Father is Lord; the Son is Lord; the Holy Spirit is Lord;  And yet there are not three lords, but one Lord.

For like as we are compelled by the Christian verity to acknowledge every Person by Himself to be God and Lord, so we are forbidden by the catholic religion to say, There be three Gods or three Lords.

The Father is made of none, neither created nor begotten.  The Son is of the Father alone, not made nor created but begotten.  The Holy Ghost is of the Father and of the Son, neither made nor created nor begotten, but proceeding.

So, there is one Father, not three Fathers; one Son, not three Sons; one Holy Ghost, not three Holy Ghosts.  And in this Trinity none is before or after another; none is greater or less than another; but the whole three Persons are coeternal together and coequal, so that in all things, as is aforesaid, the Unity in Trinity and the Trinity in Unity is to be worshiped.

Any person, therefore, that will be saved must thus think of the Trinity.

"Must" and "should" have very different meanings.

Whoever wants to be saved should think thus about the Trinity.

Furthermore, it is necessary to everlasting salvation that we also believe faithfully the incarnation of our Lord Jesus Christ. 

To say that our Lord Jesus Christ "took on flesh" actually isn't really as complete a statement as the traditional version which says "believe faithfully the incarnation."  Our Lord being God in heaven, remained God and came to earth, was born in the flesh, and was named Jesus.  First  of all, the person of the Son of  God was in heaven; and then there was the incarnation, so that there are two natures in the Son, a human nature, and a divine nature.

For the right faith is that we believe and confess that our Lord Jesus Christ, the Son of God, is God and Man; God of the Substance of the Father, begotten before the worlds; and Man of the substance of His mother, born in the world;

"God of the Substance of the Father, and "of the substance of His mother" are omitted from the LBW version.

For this is the true faith that we believe and confess; That our Lord Jesus Christ, God's Son, is both God and man.  He is God, begotten before all worlds form the being of the Father, and he is man, born in the world from the being of his mother--

Perfect God and perfect Man, of a reasonable soul and human flesh subsisting.  Equal to the Father as touching His Godhead and inferior to the Father as touching His manhood;

"As touching His Godhead" and "as touching His manhood" is a more clear definition.  Rather "in divinity," and "in humanity," only implies traits one could possess; and it is the two persons of Christ that should be clearly expressed.

Existing fully as God, and fully as man with a rational soul and a human body; equal to the Father in divinity, subordinate to the Father in humanity.

Who although He be God and Man, yet He is not two, but one Christ; 

The word "divided" is obscuring that Christ did have two distinct natures.  Use of the word "divided" in the LBW version is confusing and tends to imply that there were not two distinct and different natures. These two natures are "one Christ," however the Christ has two natures.

Although he is God and man, he is not divided, but is one Christ.

One, not by conversion of the Godhead into flesh, but by taking the manhood into God; 

The point is not why He is one (LBW says "united because") but that the divine nature took the human nature into itself.  "He does not transform deity into humanity" seems to cloud the meaning.

He is united because God has taken humanity into himself; he does not transform deity into humanity.

One altogether; not by confusion of Substance, but by unity of Person.

He is completely one in the unity of his person, without confusing his natures.

For as the reasonable soul and flesh is one man, so God and Man is one Christ;

For as the rational soul and body are one person, so the one Christ is God and man.

Who suffered for our salvation; descended into hell; rose again the third day from the dead; 

"Who suffered for our salvation" includes all things He suffered. He suffered more than just "death for our salvation."  His entire walk on earth was a suffering.  Also, "the third day" is omitted.

He ascended into heaven; He siteth on the right hand of the Father, God Almighty; from whence He shall come to judge the quick and the dead. 

At whose coming all men shall rise again with their bodies and shall give an account of their own works.  And they that have done good shall go into life everlasting; and they that have done evil, into everlasting fire.

At his coming all people shall rise bodily to give an account of their own deeds.  Those who have done good will enter eternal life, those who have done evil will enter eternal fire.

This is the catholic (Christian) faith; which except you believe faithfully and firmly, you cannot be saved."

This is the catholic faith.  One cannot be saved without believing this firmly and faithfully.