for ALL have (are) sinned (sinning) and fall short of the glory of God
Yes, all have sinned and all are
born into sin. Thus the need for redemption, a redeemer, salvation, etc. The super uber short Cliff's Notes version of the Bible is that the theme of the entire Bible (OT&NT) is Redemption. Redeeming oneself from Original Sin.
In the OT man had to use the blood of animals to redeem himself if he sinned. (*NOTE: there is a specific sacrifice for
accidental sin*). In the NT man is redeemed by the Blood of Christ.(Which proves that the 10 Commandments are still in effect or there would be no sin anymore.) Did the sacrifice in the OT for sin cleanse a man forever? Nope. Does getting saved, baptized, committing oneself to Christ cleanse a man forever? Nope.
All sins committed after salvation must be confessed, repented of and put away for good. The Holy Spirit helps us with that. No, we're not capable on our own.
That's it in a nutshell.
Do you not know that Christians are in a spiritual WAR? The Bible makes it plain. Ephesians 6:12 What do we wrestle against, or what war is there, in Once Saved Always Saved? That's a permanent vacation. That's like saying you've already departed from this fallen world. But you haven't.
It seems odd to claim I can lose salvation. because I did not live up to the standard or failed to keep myself at some level of sin which God requires.
That's because you're brainwashed like 98% of Christianity. To think that God actually requires something of you is an insult and an outrage. Modern Christians are spoiled-brat Christians. They can't be bothered to study their Bibles and the idea that they actually have to work for their salvation, just as the Bible makes clear, is preposterous to them.
It's a tragedy. And
many will say "Lord, Lord" with profound confusion that they are being rejected.