Why is it necessary to call anyone or anything a god?

It isn't.  But it does not do to leave a live God out of your calculations.

Because every reality has to have a name. If you don't call a tree a "tree", or a street a "street", how is anyone else going to know what you are talking about?

It's not.

You can call everything "blag" if you like.

"Why is blag necessary to call blag or blag a blag?"

The Christian God is the only God Who exists.  It is a sin to worship anyone or anything other than God.  The worship due to God and only to God is known as latria.

True concept of God: Allah is one and alone,he is eternal,he is neither born nor give birth,there is nothing like him

Not a necessity... just a truth. There is a living God and the way to Him, the truth about Him and the life we seek with Him is through Jesus Christ, because of who He is and what He has done.

its not necessary

a.) People have too much time on their hands.

b.) People are oppressed by government.

 It isnt as far as I´m concerned in all honesty Discovering that father christmas and the toothfairy didn´t really exist at around 7 years old led me to question my belief in gods at all you see.

Jesus is God :)