In Greek the word is G500 ἀντίχριστος antichristos used in Total KJV Occurrences: 5 antichrist, 4.  in these scriptures 1Jo 2:18, 1Jo 2:22, 1Jo 4:3, 2Jo 1:7 antichrists, 1 1Jo 2:18.  Antichristos an-tee'-khris-tos From G473 and G5547; an opponent of the Messiah: - antichrist.  This is not a comprehensive answer; but a short thought.  The anti Christ (one against Christ) is not an individual person, especially in a certain time period.   A human's average adult life span is 50 years or so and period in power could be less. Nor is it a local or global power for a limited period of human existence. Gen 3:15 And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel. There has been the spirit of the one against the Messiah (Christ) from creation.

Question: Did Yahshua (Jesus) not break the Sabbath by healing or allowing plucking of corn?

Healing is not working Luk 13:16. As Jesus asked, is it unlawful to do good on Sabbath? And His accusers had to keep quiet Mark 3:4.  Jesus also said the priests who perform their religious duties on the Sabbath or one circumcising a baby because the 8th day of its birth happened to fall on the Sabbath, is not breaking the law under their own understanding so how can healing be?   John 7:22-3 “Moses therefore gave unto you circumcision; (not because it is of Moses, but of the fathers;) and ye on the Sabbath day circumcise a man.

Question: Does a miracle performing church mean God is there?

Remember there have always been the satan’s miracle workers. The magicians of Moses’ and Daniel’s times, to today’s devil worshippers, witch doctors etc. Acts 8:9-10 states “But there was a certain man, called Simon, which before time in the same city used sorcery, and bewitched the people of Samaria, giving out that himself was some great one: To whom they all gave heed, from the least to the greatest, saying, This man is the great power of God. Act 13:6, 8 …they found a certain sorcerer, a false prophet, a Jew, whose name was Barjesus: …But Elymas the sorcerer …seeking to turn away the deputy from the faith.