God's Part, Our Part

Response to comment [from a Christian]:  [Christians are free of sin] (brackets mine)

We also have victory over death--but we will still die.

Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin [Rom. 6:6].
"“Knowing this”—these are things we know.
When Paul says your “old man” is crucified with Him, he doesn’t mean your father; he means your old nature is crucified with Him. “That the body of sin might be destroyed”—the word destroyed is katargeo, meaning “to make of none effect, to be paralyzed or canceled or nullified”—“that henceforth we should not serve sin.” Paul is not saying that the old nature is eradicated. He is saying that since the old man was crucified, the body of sin has been put out of business, so that from now on we should not be in bondage to sin.
For he that is dead is freed from sin [Rom. 6:7].
For he who died is declared righteous from sin. He is acquitted. That is his position.
Now if we be dead with Christ, we believe that we shall also live with him [Rom. 6:8].
If we died with Christ, we believe that we shall also be living with Him both here and hereafter. We share His resurrection life today, and we will be raised from the dead someday.
Knowing that Christ being raised from the dead dieth no more; death hath no more dominion over him [Rom. 6:9].
“Knowing”—this is something else we are to know.
“He ever liveth” is the victor’s chorus. The glorified Christ says, “I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death” (Rev. 1:18). The Resurrection opens up eternity to Christ, and it will open up eternity to those who will trust Him."
McGee, J. V. (1997, c1981). Thru the Bible commentary. Based on the Thru the Bible radio program. (electronic ed.) (4:683-684). Nashville: Thomas Nelson.

Response to comment [from a Catholic]:  [Heaven]  "How does God know you will behave yourself once you get there?"

We have already started behaving ourselves here (Ro 6:6).  If this has not happened--if your faith has not changed you, then something is seriously wrong with your faith.   

"I started a thread on holiness..."

An oxymoron (Ps 53:3).

See:

Is A Roman Catholic Christian An Oxymoron?

God's Part Our Part