Church of God in the New Testament is not the name of an organization. Rather, it refers to the spiritual condition of a particular people. Church of God are the people themselves and their spiritual condition. Church comes from a Greek word Ekklesia which means called out ones.
Notice the CALLED and the OUT in this verse:
1Pe 2:9 But you are a chosen generation, a royal priesthood, a holy nation, His own special people, that you may proclaim the praises of Him who CALLED you OUT of darkness into His marvelous light;
Called out of spiritual darkness into God's marvelous light which is Christ Jesus. That's their spiritual condition. That's the Church of God.
God called through the Gospel. They responded positively. They become God's called-out ones or the church of God. Their spiritual condition is marked by heeding God's call.
Our responsibility is not to look for an organization, rather, our individual responsibility, wherever we are, is to heed God's call to repent and trust in the Lord Jesus for salvation. And once you have done that, it's the Shepherd's responsibility to bring you into His local flock, providentially, by arranging events and through your desires to fellowship with others like you who have heeded His call. "... the Lord added to the church daily those who were being saved." Ac 2:47
Church of God in the Bible is not the name of a religious organization. It's like the word "believers" in the New Testament. The word "believers" is not a name of an organization in the NT. Rather, it refers to people and their spiritual condition. It refers to a reality in their individual lives; they are believers. They have trusted in Christ for salvation.