GOSPEL NUGGET #618

 Church of God is not the name of God's religious organization. It does not refer to a visible and external organization. Rather, it refers to the spiritual condition of certain people. The word "Church" comes from a Greek word which means to be called out. 

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;

It refers to the condition of people who were called out of spiritual darkness into God's marvelous light. 
It's not a visible and external religious organization, no, rather, it's a spiritual experience and condition that one must undergo and be brought to.

Motherhood is not a visible and external organization. No, it's an experience and a condition. So it is with the Church of God, the called-out ones of God. You must personally experience and respond to God's call and then and only then can you be part of the Church of God, the called-out ones of God.

How does God call a sinner?

  2Th 2:14 to which He CALLED YOU BY OUR GOSPEL, for the obtaining of the glory of our Lord Jesus Christ.

The Gospel is the message of salvation about the death of the Lord Jesus for our sins and His subsequent resurrection (see 1 Cor. 15:1-4). The moment we trust in the Lord Jesus Christ and what He did on the cross for our salvation, that's the very moment we are called out from spiritual darkness into God's light. That's the moment we can say truly that we have been called out from darkness to light.