Ah, here we go!
The bible is a story of men going to God and going away from God. He often said, return to Me and I will heal you, give you back all you have lost, be merciful, etc.
Examine even just yourself. Do you go away from trust in Him and again back to trusting Him when you realize what you have done?
So then justification is gained and lost as your faith waxes and wanes? I'm not trying to put words into your mouth, just to understand your view.
I see justification as God rendering us not guilty. I see this as happening under the old covenant as sins are covered by sacrifices, and when they would come in faith to God, like you said, confess, to say the same as God, agree with Him about their sin, they would be justfied, that is, declared not guilty of their sin.
Under the old covenant, this would be gained and lost, like Ezekiel 18, the righteous man who does evil, his righteousness is forgotten.
But that is his righteousness.
In being recreated as in the new covenant, reborn, again referring to Ephesians 4, our "new man" is created in God's Own pattern, in righteousness and true holiness. This is righteousness and holiness imparted to us by virtue of a new creation.
Not being our own righteousness, it is not gained or lost once given. I know many will disagree with me here.
The difference is in being accepted on the basis of my righteousness, but I falter, or being accepted based on Jesus' righteousness, which does not falter.
2 Timothy 2
11 It is a faithful saying: For if we be dead with him, we shall also live with him:
12 If we suffer, we shall also reign with him: if we deny him, he also will deny us:
13 If we believe not, yet he abideth faithful: he cannot deny himself.
If we believe not, this is literally, If we are being faithless, present active, if that's us right now, yet He remains faithful, and in fact it's His faith in us that matters,
Galatians 2
19 For I through the law am dead to the law, that I might live unto God.
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.
21 I do not frustrate the grace of God: for if righteousness come by the law, then Christ is dead in vain.
By the faith OF the Son of God, this is His faith, by which I live, just like the Septuagint translation of Habakkuk, the just, by My faith, they live.
Much love!