No it’s not a false Gospel…Jesus was the Passover Lamb, when He made atonement for sin at the Cross the Veil of the temple was torn in 2 from top to bottom by God. That shows the animal sacrifices are done and way into the Holy of Holies was now through Jesus Christ, He is the once for all sacrifice for sin.
How have your sins been atoned for? You are still in them and the wrath of God rests on you.
Once you break the law even once you’re guilty, we all are, so you think keeping some of the law and doing the best you can will be good enough? That’s a false gospel and no gospel at all
Well, if Yeshua made atonement on the cross, then you can throw away the phone number of your doctor, for you would be healed. The only ones who are healed are those who confess their sins and have a righteous person, someone who does right, pray for them, as in the case of Elijah (James 5:15-16). As for the day of atonement, as in the feast of Atonement, Yom Kippur, is when Judah will be "restored" (Hosea 6:1-2 & Joel 3:1-2), happens at the time that the nations/Gentiles are judged, as in the "day of the LORD" (Joel 2:31-32 & 3:1-2), when those in Jerusalem and on Mount Zion will "escape", as in being saved from death. On Yom Kippur, the sins are dealt with, with the blood of a bull. The sacrifice of the lamb is with respect to the feast of Unleavened Bread, whereas the angel of death flies over those with the blood of the lamb on their doorpost, which would refer to the "escape" of those on Mount Zion and in Jerusalem, during the "day of the LORD", from the angels of death. Those on Mount Zion are those who keep the Commandments, and nail the Law to their doorposts, as stated in Law and the prophets (Dt 6:9). It is the gospel of the kingdom of heaven which will be preached in the end (Matthew 24:14), whereas those who follow the "message' of the "enemy"/"devil", the message of Paul, will be gathered and thrown into the fire (Matthew 13:30). At that time, I don't think your oven mitts will protect you.
Deuteronomy 6:9 You shall write them on the doorposts of your house and on your gates.