dedication - what kind of body did Christ have? A perfect body or a "sinful" body?

As for "A sudden DNA change would require God to recreate Adam and Eve into carnal beings by changing the genetic codes in their bodies", that would mean that God is the author of sin and He is not.

Let me ask a question, is a viral infection a "sudden DNA change"? Or is it a "progressive DNA change"? It is not the latter.

Christ's physical body came from the DNA passed down from King David and the line of descendants to Mary. He was fully human, "tempted in all points as we are".

But His mind was completely surrendered to the Holy Spirit and to God from the very beginning. He was born of the Spirit from birth, He didn't need to be "born again" of the spirit, like we must.

In this sense He was not altogether like us, for we must be born again of the Spirit.

I agree -- and I don't think there was a "sudden DNA change" either. 

A viral infection is when a foreign substance attacks our cells, and the body's immune system has to fight it off to restore health. While sin is often compared to a virus, due to its destructive effects on both our spirituality and health, it is not literally a virus. Therefore I really do not see approaching this symbolic representation in an absolute literal way.

Christ, who knew not the least moral taint or defilement of sin, took our nature in its deteriorated condition. {16MR 115.3}...

By taking upon Himself man's nature in its fallen condition, Christ did not in the least participate in its sin. He was subject to the infirmities and weaknesses of the flesh with which humanity is encompassed, "that it might be fulfilled that was spoken by the prophet Esaias, Himself took our infirmities and bare our sicknesses." He was touched with the feeling of our infirmities, and was in all points tempted like as we are. And yet He was without a spot. {16MR 116.3} ...

The enmity put between the seed of the serpent and the seed of the woman was supernatural. {16MR 118.1}...

Everything had been transformed by the working of the arts of Satan. {16MR 122.3}

He was born of the Holy Ghost. In other words, Jesus Christ was born again. He came from heaven, God's first-born, to the earth, and was born again. But all in Christ's work goes by opposites for us: he, the sinless one, was made to be sin, in order that we might be made the righteousness of God in him. He, the living one, the prince and author of life, died that we might live. He whose goings forth have been from the days of eternity, the first-born of God, was born again, in order that we might be born again. {August 1, 1899 ATJ, ARSH 487.2}

If Jesus Christ had never been born again, could you and I have ever been born again?—No. But he was born again, from the world of righteousness into the world of sin; that we might be born again, from the world of sin into the world of righteousness. He was born again, and was made partaker of the human nature, that we might be born again, and so made partakers of the divine nature. He was born again, unto earth, unto sin, and unto man, that we might be born again unto heaven, unto righteousness, and unto God. {August 1, 1899 ATJ, ARSH 487.3}

The forgiveness of sins is not the sole result of the death of Jesus. He made the infinite sacrifice, not only that sin might be removed, but that human nature might be restored, rebeautified, reconstructed from its ruins, and made fit for the presence of God.  {5T 537.1}

If those who speak so freely of perfection in the flesh, could see things in the true light, they would recoil with horror from their presumptuous ideas. {2SM 32.2}

In this work we are to be laborers together with God. Much may be done to restore the moral image of God in man, to improve the physical, mental, and moral capabilities. Great changes can be made in the physical system by obeying the laws of God and bringing into the body nothing that defiles. And while we cannot claim perfection of the flesh, we may have Christian perfection of the soul.

When human beings receive holy flesh, they will not remain on the earth, but will be taken to heaven. While sin is forgiven in this life, its results are not now wholly removed. It is at His coming that Christ is to "change our vile body, that it may be fashioned like unto his glorious body" (Philippians 3:21). . . .  {2SM 33.3}

All come forth from their graves the same in stature as when they entered the tomb. Adam, who stands among the risen throng, is of lofty height and majestic form, in stature but little below the Son of God. He presents a marked contrast to the people of later generations; in this one respect is shown the great degeneracy of the race. But all arise with the freshness and vigor of eternal youth. In the beginning, man was created in the likeness of God, not only in character, but in form and feature. Sin defaced and almost obliterated the divine image; but Christ came to restore that which had been lost. He will change our vile bodies and fashion them like unto His glorious body. The mortal, corruptible form, devoid of comeliness, once polluted with sin, becomes perfect, beautiful, and immortal. All blemishes and deformities are left in the grave. Restored to the tree of life in the long-lost Eden, the redeemed will "grow up" (Malachi 4:2) to the full stature of the race in its primeval glory. The last lingering traces of the curse of sin will be removed, and Christ's faithful ones will appear in "the beauty of the Lord our God," in mind and soul and body reflecting the perfect image of their Lord. Oh, wonderful redemption! long talked of, long hoped for, contemplated with eager anticipation, but never fully understood. {GC 644.3}

Do believers sin and not sin simultaneously? Are they righteous and unrighteous at the same time? Can they mature in the fruits of the Spirit and cultivate sinful traits of character in the same instant?

Sinning can happen in several different ways. Sin is the transgression of the law. We can sin in thoughts, words, and deeds. There is also a record of the sins we have committed in the past.

Why do you ask?

Also, would you mind answering the questions I posted above?

The apostle gives us the true definition of sin. "Sin is the transgression of the law." {Con 75.2}

Now, we want to understand what sin is--that it is the transgression of God's law. This is the only definition given in the Scriptures. {FW 56.1}

The only definition we find in the Bible for sin is that "sin is the transgression of the law" (1 John 3:4). {1SM 320.1}

A terrible doom awaits the sinner, and therefore it is necessary that we know what sin is, in order that we may escape from its power. John says, "Whosoever committeth sin transgresseth also the law; for sin is the transgression of the law" (1 John 3:4). Here we have the true definition of sin; it is "the transgression of the law." {FW 117.2}

Sin is an intruder, for whose presence no reason can be given. It is mysterious, unaccountable; to excuse it is to defend it. Could excuse for it be found, or cause be shown for its existence, it would cease to be sin. Our only definition of sin is that given in the word of God; it is "the transgression of the law;" it is the outworking of a principle at war with the great law of love which is the foundation of the divine government. {GC 492.2}

What is to bring the sinner to the knowledge of his sins unless he knows what sin is? The only definition of sin in the Word of God is given us in 1 John 3:4. "Sin is the transgression of the law." The sinner must be made to feel that he is a transgressor. Christ dying upon the cross of Calvary is drawing his attention. Why did Christ die? Because it was the only means for man to be saved. {OHC 141.3}

Then if this great and infinite sacrifice has been made in our behalf, let us ask ourselves, What are we doing? Do we say, "Believe, believe on Christ, and that is all"? If we have not the faith that works by love, and purifies the soul from every stain of sin, then we have a spurious faith. Christ is not the minister of sin. And what is sin? The only definition given in God's word is, "Sin is the transgression of the law;" and the apostle Paul declares, "Where no law is, there is no transgression." The law is the great standard that will measure every man's character. {BEcho, June 11, 1894 par. 7}

So, the question remains - What constitutes an unknown sin? Which sins can born-again, baptized believers commit without realizing it?

In particular, which sins do believers commit unknowingly who have learned how to live in harmony with "all things whatsoever" Jesus commanded?

I'm not a fan of the "state of being" (Sin) versus "state of doing" (sins) explanation of sin. I like the following definitions: