Walter Vieth is not teaching we should sin and does teach we need to be perfect but can only do that through Christ. His point was we will have a sinful nature until the close of probation. Do you have anything that shows we can't sin before the close of probation?
The thing is, Walter is saying we will continue having a 'sinful nature' till our bodies are changed at the second coming from corruptible (or sinful nature) to incorruptible (or perfect bodies like Adam), and he doesnt clarify what he means by that or go further into the text it refers to. Now the problem is that if our minds are corrupted and full of sin and iniquity, the Christ will turn us aside at the Second Coming and say 'I do not know you'.
Matthew 7:23
And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.
Luke 13:27
But he shall say, I tell you, I know you not whence ye are; depart from me, all ye workers of iniquity.
Our minds must be transformed and sanctified before, at the close of probation and sealed so that iniquity doesnt work in our minds from temptation of Satan and evil thoughts can no longer come upon us. Our bodies are what will have the corruptible sinful nature till the end, our minds must be changed before Christ comes.
Romans 12:2
And be not conformed to this world:
but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.
And it is by faith through Christ.
Galatians 2:20
I am crucified with Christ: nevertheless I live; yet not I, but Christ liveth in me: and the life which I now live in the flesh
I live by the faith of the Son of God, who loved me, and gave himself for me.
And we see that we are sealed unto everlasting life thought this change, so its not the change or transformation of the body.
John 6:27
Labour not for the meat which perisheth, but for that meat
which endureth unto everlasting life, which the Son of man shall give unto you:
for him hath God the Father sealed.
2 Corinthians 1:22
Who hath also sealed us,and given the earnest of the Spirit in our hearts.
Ephesians 1:13
In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed,
ye were sealed with that holy Spirit of promise,
And it happens before the Second Coming..
Ephesians 4:30
And grieve not the holy Spirit of God,
whereby ye are sealed unto the day of redemption.
Revelation 7:3
Saying, Hurt not the earth, neither the sea, nor the trees,
till we have sealed the servants of our God in their foreheads.
We are sealed and prepared to face Christ at His coming and then our bodies are transformed as "we shall all be changed", the resurrected dead as well as those alive on earth, back to what they were in the Garden of Eden before sin so death can be overcome.
1 Corinthians 15:51-54
51 Behold, I shew you a mystery;
We shall not all sleep, but we shall all be changed,
52 In a moment, in the twinkling of an eye, at the last trump: for the trumpet shall sound, and the dead shall be raised incorruptible, and we shall be changed.
53 For this corruptible must put on incorruption, and this mortal must put on immortality.
54
So when this corruptible shall have put on incorruption, and this mortal shall have put on immortality,then shall be brought to pass the saying that is written, Death is swallowed up in victory.