"Call" in NT

I just realized that there are several (slightly) different Greek words in the NT for "call". They are related, and the differences appear to be superficial, like abbreviations and "conjugations" and "declensions" w/ various different suffixes. Or something along those lines.

However, the net effect is that the following three Strong's Numbers are all essentially the same Greek word. You must, therefore, do at least three parallel Strong's searches when making doctrinal arguments about "Calling" in Christian theology:

kletos (G2822)
klesis (G2821)
kaleo (G2564)

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The following are also related:

keleuo (G2753)
keleusma (G2752)

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Matt 16:18
And I say also unto thee, That thou art Peter, and upon this rock I will build my church (ekklesia, G1577); and the gates of hell shall not prevail against it.​

NOW, ekklesia (G1577) is a compound of the Greek prefix "ex, ek" and the Greek word "kaleo" (G2564).

IOW, ekklesia = ex + kaleo = out + called = "called out".

I also need to add that the word "build" comes from the Greek verb oikodomeo (G3618) which means "build a house".

The Messiah will build the house of his ekklesia upon the rock of St. Peter. This means that the Messiah will build the house of his "called out" ones.

Interestingly, we also read, "many are called, but few are chosen" (Matt 20:16, 22:14). The word "called" here is essentially the same as the "called" of ekklesia.

Could this possibly indicate that not every member of the church (ekklesia) will be chosen? Is this what John Calvin meant when he talked about the "visible church" (ekklesia, those called out) and the true "invisible church" of the true elect (those not only called out, but chosen)?