Christ Ahnsahnghong did testify He was Christ…Through the Bible
When Jesus appeared 2,000 years ago, He didn’t need to say “I’m Christ; I’m God who came in the flesh,” because He already testified being God through the things He said… Let me explain:
Jeremiah 31:31 – “The time is coming,’ declares the LORD (Jehovah), “when I will make a new covenant with the house of Judah….”
According to the prophecy of Jeremiah, which was written before Jesus was born, the LORD Jehovah is the one who promised to make the New Covenant; this means that no one else can establish the New Covenant except God Himself. In this way, when God comes He doesn’t need to say: “I’m God,” but just simply establish the New Covenant, and those who know the prophecy will understand who God is. Let’s see another verse:
Luke 22:20 – In the same way, after the supper he took the cup, saying, “This cup is the new covenant in my blood, which is poured out for you”
Jesus uttered the words: “This…is the new covenant…” By these words, what was He ultimately saying? I am God.
Now the reason why this is important is that Christ Ahnsahnghong did the same thing.
In chapter 1 of the book The Mystery of God and the Spring of the Water of Life, Christ Ahnsahnghong writes:
“Then, who will open up what the seven thunders said and break its seals? … As it is written, ‘A Lamb, looking as if it had been slain,’ the Lamb to come secretly in the name of David in the last days is to open what the seven thunders said and to break its seven seals.”
Christ Ahnsahnghong said that only the Lamb who comes again, meaning Second Coming Christ, can open what the seven thunders have said. Christ Ahnsahnhong titled the first chapter of book:

Even if you do not know the meaning of the seven thunders, you can understand that by Christ Ahnsahnhong claiming to unseal the seven thunders, he is claiming to be Second Coming Christ.
Although there are many more records of Christ Ahnsahnghong claiming to be Christ through His writings, this one is enough. Now I have a question for those who oppose the Church of God:
Will you stand up to your words?
“…I am open to hearing your arguments, and to being corrected if I am found wrong.… Can you prove me wrong? Can you show me any error in my arguments? … If something is wrong, then please correct it and set the record straight…”
Now that you have seen where your error is in this aspect… Are you willing to apologize and correct your erroneous arguments? If the answer is no, then you owe it to yourself, and to God, to stop speaking about what you don’t understand.