I agree that sometimes a person can get by on a false profession, however it does not follow that a true believer then cannot know that he is saved. That is a leap in logic.
Not a leap in leap in logic, just a natural conclusion. Further in your post you introduce Mt 7:21, for which I thank you. Please note, those about whom the Lord is speaking had no idea they were not true believers; had you simply looked at their fruits - healing and other wonders, casting out demons, prophesying all in Christ’s name - you could not say they weren’t true believers.
I affirm that God knows the heart, and yet that other people cannot be too quick to judge the professing believer (until their fruit becomes clearly evident). However - the assurance of a man’s own salvation does not come from the approval of other men, but from God the Holy Spirit Alone. The Bible teaches that *“The Spirit Himself bears witness with our spirit that we are children of God.” *(Romans 8:16). Again, you are making a leap in logic, attempting to connect that which is not connected.
You are attempting to disconnect that which is intimately connected. I’d like to finish your quote of Rom 8:16:
16 The Spirit Himself testifies with our spirit that we are children of God,
17 and if children, heirs also, heirs of God and fellow heirs with Christ,
if indeed we suffer with Him so that we may also be glorified with Him
It is the parent/child relationship that testifies the loudest against your position. You and I, as fathers, can raise our children correctly, providing them every advantage (spiritually) and we still are not guaranteed they will follow the path they should. They have, always, the choice, the free will, to choose against us.
Should a child choose to leave, the child would have to be the one to initiate the return, first by a true contrition for the bad behavior, then by a firm decision to amend his ways, and finally a reconciliation with the father.
1st John is clear. If someone ever “falls away” - or manifests themselves to be lost, then this is evidence that they were never saved. Look at the passage: “They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us: but they went out, that they might be made manifest that they were not all of us.” (1 John 2:19)
Clearly John teaches that if anyone is truly apart of the family of God, then they will continue therein. He teaches further that if they abandon the faith and the family of God, ultimately rejecting the gospel and Christ - then they were never a part of the family, and clearly never knew Christ.
Again, you miss the obvious. It is not until the turning away and the decision to not return that one can say that person was not truly part of the family. Any one of us could choose, based on our own free will, to turn away from God tomorrow.
Again, it comes down to, only until one crosses the finish line can one be asureede they will finish the race.
This is what Jesus taught in Matthew 7. He made it clear that on the last day “many” professing Christians would come to him and say, "Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?’ (vv. 21-22). Jesus said that he will turn to them and respond that he “never knew them” - not that he knew them at one point, and then they lost their salvation and were cut off.
Contrary to your assertions above, Scripture is in agreement with my position.
While you attempt to read into Scripture that which is not there, or attempt to fit your theology into prooftexts, both Scripture and Tradition attest to the need to reject presumption and persevere to the end.
Rom 11:22
Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if
you continue in His kindness; otherwise you also will be cut off.
1 Cor 9
26 Therefore I run in such a way, as not without aim; I box in such a way, as not beating the air; 27 but
I discipline my body and make it my slave, so that, after I have preached to others, I myself will not be disqualified.
1 Cor 10
Therefore let him who thinks he stands take heed that he does not fall.
Phil 2:12
So then, my beloved, just as you have always obeyed, not as in my presence only, but now much more in my absence,
work out your salvation with fear and trembling;
Matthew 13:18-23
18 "Hear then the parable of the sower.
19 "When anyone hears the word of the kingdom and does not understand it, the evil one comes and snatches away what has been sown in his heart. This is the one on whom seed was sown beside the road.
20 "The one on whom seed was sown on the rocky places, this is the man who hears the word and immediately receives it with joy;
21 yet he has no firm root in himself, but is only temporary, and when affliction or persecution arises because of the word, immediately he falls away.
22 "And the one on whom seed was sown among the thorns, this is the man who hears the word, and the worry of the world and the deceitfulness of wealth choke the word, and it becomes unfruitful.
1 Corinthians 15:1-2
1 Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand,
2 by which
also you are saved, if you hold fast the word which I preached to you, unless you believed in vain.
Finally, in Mt 25, each parable speaks against the idea of the “perseverance of the saints.”