Christianity hasn't changed. Man has.You're very right. Modern pro-gun Christianity is not really ancient Christianity at all. But religions evolve.
The government shut down businesses in general for COVID, including churches. If the government had allowed churches to remain open while shutting down other businesses, it would be favoring religion and thus violating the first amendment.
Malachi 3:6 6"I the LORD do not change. So you, the descendants of Jacob, are not destroyed.
James 1:17 17Every good and perfect gift is from above, coming down from the Father of the heavenly lights, who does not change like shifting shadows.
Numbers 23:19 19God is not human, that he should lie, not a human being, that he should change his mind. Does he speak and then not act? Does he promise and not fulfill?
And I am a child of the One who does not change , so I do not change or misapply His word. I talk the talk, and walk the walk of my God . For I am told to be Holy as He is Holy , and to be perfect, for my Heavenly Father is perfect. There is only one Brand of Christianity and it is the Brand taught us in scripture . We are able to uphold that Brand and Standard through humble obedience- faith! The Holy Spirit with the Holy written word gives correction and gives a Christian the proper tools to fight the enemy.
Concerning the faithful-
2 Timothy :
10You, however, have observed my teaching, my conduct, my purpose, my faith, my patience, my love, my perseverance, 11my persecutions, and the sufferings that came upon me in Antioch, Iconium, and Lystra. What persecutions I endured! Yet the Lord rescued me from all of them. 12Indeed, all who desire to live godly lives in Christ Jesus will be persecuted, 13while evil men and imposters go from bad to worse, deceiving and being deceived.
(See the imposter Christians are addressed so you aren't telling me a thing)
14But as for you, continue in the things you have learned and firmly believed, since you know from whom you have learned them. 15From infancy you have known the Holy Scriptures, which are able to make you wise for salvation through faith in Christ Jesus. 16All Scripture is God-breathed and is useful for instruction, for conviction, for correction, and for training in righteousness, 17so that the man of God may be complete, fully equipped for every good work.
His word is One as He is One. He is not the author of confusion.