We spend our whole lives thinking defensively. We know that we cannot trust other human beings. They fail us. They hurt us. They disappoint us. We put locks on our doors. How are we suddenly - in an instant - to think differently? I believe it will take time to heal all the wounds, and the damage that sin has wrought.
Many people have died when they were babes in the Word, just recently converted to Jesus Christ. Even "seasoned" believers will admit they still need forgiveness quite often. I personally do not believe we will reach "perfection" until we experience the fullness of the New Covenant. And that fullness is not experienced UNTIL we are returned to the land.
I used to beat myself up over the whole "perfection" doctrine, believing that I had to become "perfect" so that Jesus could return. I wondered why the LORD did not fulfill his promise to make us perfect. I thought I was lacking in faith somehow. An old friend told me to read Ezekiel 36 : 23-28, looking for WHEN the New Covenant is fulfilled.
Ezekiel 36:23 "And I will sanctify My great name, which has been profaned among the nations, which you have profaned in their midst; and the nations shall know that I am the LORD," says the Lord GOD, "when I am hallowed in you before their eyes. 24 "For I will take you from among the nations, gather you out of all countries, and bring you into your own land. 25 "Then I will sprinkle clean water on you, and you shall be clean; I will cleanse you from all your filthiness and from all your idols. 26 "I will give you a new heart and put a new spirit within you; I will take the heart of stone out of your flesh and give you a heart of flesh. 27 "I will put My Spirit within you and cause you to walk in My statutes, and you will keep My judgments and do them. 28 "Then you shall dwell in the land that I gave to your fathers; you shall be My people, and I will be your God." (NKJ)
This is the SAME covenant referenced in Hebrews 8:10, and Jeremiah 31:31-33. And it is fulfilled for Israel redeemed AFTER she is returned to "the land".
When do we "return to the land"? Answer: AFTER the return of Christ and AFTER the desolation of the 7th millennium.
I no longer believe that most will be "perfect" before the return of Christ in glory. They will be "perfect" in the eyes of God, only because they are covered with Christ's righteousness. Perhaps the 144,000 WILL reach a state of faith and relative spiritual perfection, but that remains to be seen.
I have turned my "perfection" over to Jesus. I don't worry about it any more. My perfection is His job. My job is to believe in Him.