If you want to see what sin really is

(Philpot, "Sin Condemned and Righteousness Fulfilled")

To cast the sinning angels out of heaven;
to banish Adam from Paradise;
to destroy the old world by a flood;
to burn Sodom and Gomorrah with fire from heaven–
these examples of God's displeasure against sin were
not sufficient to express His condemnation of it. He
would therefore take another way of making it manifest.

And what was this?

By sending His own Son out of His bosom, and offering
Him as a sacrifice for sin upon the tree at Calvary, He
would make it manifest how He abhorred sin, and how
His righteous character must forever condemn it.

See here the love of God to poor guilty man in not
sparing His own Son; and yet the hatred of God against
sin, in condemning it in the death of Jesus.

It is almost as if God said, "If you want to see what
sin really is
, you cannot see it in the depths of hell. I
will show you sin in blacker colors still– you shall see
it in the sufferings of My dear Son; in His agonies of
body and soul; and in what He as a holy, innocent
Lamb endured under My wrath, when He consented
to take the sinner's place."

What wondrous wisdom,
what depths of love,
what treasures of mercy,
what heights of grace
were thus revealed and brought to light in God's
unsparing condemnation of sin, and yet in His
full and free pardon of the sinner!

If you have ever had a view by faith of the suffering
Son of God in the garden and upon the cross; if you
have ever seen the wrath of God due to you, falling
upon the head of the God-Man; and viewed a bleeding,
agonizing Immanuel; then you have seen and felt in
the depths of your conscience what a dreadful thing
sin is. 
Then the broken-hearted child of God "looks
unto Him whom he has pierced, and mourns and grieves
bitterly for Him, as for a firstborn son who has died."

Under this sight he feels what a dreadful thing sin is.

"Oh," he says, "did God afflict His dear Son? Did
Jesus, the darling of God, endure all these sufferings
and sorrows to save my soul from the bottomless pit?
O, can I ever hate sin enough? Can I ever grieve and
mourn over it enough? Can my stony heart ever be
dissolved into contrition enough, when by faith I see
the agonies, and hear the groans of the suffering,
bleeding Lamb of God?"

Christians hate their sins. They hate that sinful, that
dreadfully sinful flesh of theirs which has so often,
which has so continually, betrayed them into sin.
And thus they join with God in passing condemnation
upon the whole of their flesh; upon all its actings and
workings; upon all its thoughts and words and deeds;
and hate it as the prolific parent of that sin which
crucified Christ, and torments and plagues them.