As to the general claim, I think we get too sensitive when others claim our religion is false, because it seems so obvious to me that that must be what most people think.
Have a SPECIFIC claim then!
KJV 1 Corinthians 4:17
For this cause have I sent unto you Timotheus, who is my beloved son, and faithful in the Lord, who shall bring you into remembrance of my ways which be in Christ, as I teach every where in every church.
KJV 1 Corinthians 11:2
Now I praise you, brethren, that ye remember me in all things, and keep the ordinances, as I delivered them to you.
KJV 2 Thessalonians 2:15
Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle.
KJV 2 Timothy 1:13
Hold fast the form of sound words, which thou hast heard of me, in faith and love which is in Christ Jesus.
KJV 2 Timothy 3:14-15
14. But continue thou in the things which thou hast learned and hast been assured of, knowing of whom thou hast learned them;
15. And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
NIV Galatians 1:6-9
6. I am astonished that you are so quickly deserting the one who called you by the grace of Christ and are turning to a different gospel--
7. which is really no gospel at all. Evidently some people are throwing you into confusion and are trying to pervert the gospel of Christ.
8. But even if we or an angel from heaven should preach a gospel other than the one we preached to you, let him be eternally condemned!
9. As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let him be eternally condemned!
ANYBODY???
Like this fine looking fellow???
2 Corinthians 11:12-15
12. And I will keep on doing what I am doing in order to cut the ground from under those who want an opportunity to be considered equal with us in the things they boast about.
13. For such men are false apostles, deceitful workmen, masquerading as apostles of Christ.
14. And no wonder, for Satan himself masquerades as an angel of light.
15. It is not surprising, then, if his servants masquerade as servants of righteousness. Their end will be what their actions deserve.
Like THESE guys??
17 It no sooner appeared than I found myself delivered from the enemy which held me bound. When the light rested upon me I saw two Personages, whose brightness and glory defy all description, standing above me in the air. One of them spake unto me, calling me by name and said, pointing to the otherThis is My Beloved Son. Hear Him!
Ephesians 2:1-2
As for you, you were dead in your transgressions and sins, in which you used to live when you followed the ways of this world and of the ruler of the kingdom of the air, the spirit who is now at work in those who are disobedient.
My term “general claim” was not meant as a contrast to a specific claim, but to reference the entirety of the discussion, outside the specific example of one faith and practice.