Ekklesia: Christ Calling

Who or what is the Ekklesia. We see that the word has been translated into church. When we look at the word closer its meaning is calling out, or called out ones. In Matt. 16:18 we read,"And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it." Is this talking about the Church below or in Heaven?

We will be looking into this word and see how Christ is building his Ekklesia and how this relates to election.

For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. (Romans8:29)