I think this clarification helps, because I agree with much of what you are describing when it comes to consecration. A believer should increasingly surrender every area of life to the Lord rather than holding parts of it back. That is certainly biblical.
But I still think we need to distinguish that ongoing growth from what 2 Peter 1:10-11 actually calls the “entrance.”
Peter is already writing to people who “have obtained like precious faith with us” ~2 Peter 1:1, and he says they have been made “partakers of the divine nature” ~2 Peter 1:4. He then tells these believers to diligently add virtue, knowledge, temperance, patience, godliness, brotherly kindness, and charity to their faith.
Then comes verse 11: “For so an entrance shall be ministered unto you abundantly into the everlasting kingdom of our Lord and Saviour Jesus Christ.” ~2 Peter 1:11
I don't see anything there saying that this entrance is a deeper spiritual condition believers may enter during this present life. Peter calls it entrance into the “everlasting kingdom.” The growth and diligence are taking place now. The entrance into that everlasting kingdom is what lies ahead.
Think of a child being born into a family. The child does not become more and more part of the family as he grows. He is already in the family. But over time he matures, learns obedience, develops character, and grows into what he already is. That is much closer to the biblical picture of the Christian life. We are already “in Christ,” but we are still growing in grace and obedience.
Another illustration is entering a race. Once the runner has entered the race, he is in it. He still has to run, endure, and finish. His progress through the race is real, but he is not repeatedly entering the race at deeper levels. Scripture says, “let us run with patience the race that is set before us” ~Hebrews 12:1. Growth and perseverance happen after the entrance.
So yes, there is an ongoing process in the Christian life. We grow, yield, obey, repent, mature, and become increasingly fruitful. I am completely with you there.
Where I still have to draw the line is when that biblical process of sanctification is described as the Lord finally “taking full possession” of someone, or as presently entering something beyond what every believer already possesses in Christ. I still need to see Scripture actually say that before I can accept it.
I think of it that as the bible says, we ARE complete in Him, because our new man is complete in Him, having been "made in the image of He who created it".......but it is a question of how much of Christ and the new man are we actually manifesting? and how much are we still living through (manifesting) our old man? Where it says we must "lose" our life (psuche) for His sake in order to find it, it is talking about losing the life we live through our old man in order to "find" resurrection life by living through (manifesting) the new man and Christ in us.
I hope these may be helpful:
Act 14:22
Confirming the souls of the disciples, and exhorting them to continue in the faith, and that
we must through much tribulation enter into the kingdom of God.
Heb 12:10-11
For they verily for a few days
chastened us after their own pleasure; but he for our profit, that we might be partakers of his holiness.
Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.
Rom 8:18-19
For I reckon that the sufferings of this present time are not worthy to be compared with the glory which shall be revealed in us.
For the earnest expectation of the creature waiteth for
the manifestation of the sons of God.
Eph 4:13
Till we all come in the unity of the faith, and of the knowledge of the Son of God,
unto a perfect man, unto the measure of the stature of the fulness of Christ:
Gal 2:20
“I have been crucified with Christ
; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me.
But I believe it is like Paul said...he was of the mind that he had not yet attained so long as he was alive and still running his race in this world and instructs others who are "perfect" to be of that same mind as he was (humility), of not counting themselves to be perfect and having already attained but continuing to run the race and reaching for what is still ahead:
Phl 3:7-16
But what things were gain to me, those I counted loss for Christ.
Yea doubtless, and I count all things but loss for the excellency of the knowledge of Christ Jesus my Lord:
for whom I have suffered the loss of all things, and do count them but dung, that I may win Christ,
And be found in him, not having mine own righteousness, which is of the law, but that which is through the faith of Christ, the righteousness which is of God by faith:
That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;
If by any means I might attain unto the resurrection of the dead.
Not as though I had already attained, either were already perfect: but I follow after, if that I may apprehend that for which also I am apprehended of Christ Jesus.
Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before,
I press toward the mark for the prize of the high calling of God in Christ Jesus.
Let us therefore, as many as be perfect, be thus minded: and if in any thing ye be otherwise minded, God shall reveal even this unto you.
Nevertheless, whereto we have already attained, let us walk by the same rule, let us mind the same thing.
