My blog is showing white background behind the texts instead of showing the orig

That is probably because you have set a text background colour to your posts.

Open each of your posts in Edit mode. Click the HTML tab. Search for 

background-color: white;

You will find the above code at many places. Delete all occurences of that code snippet. 

( Before editing your HTML, save a copy of the original HTML so that you can revert back if you make any mistakes )

For once Ranjith is wrong YaY 

To the OP's question, you have copy pasted the text from the word document or other source.  This causes the white background behind the text.  While pasting you should choose "PASTE IN PLAIN TEXT' from the right click menu and you wont get this white background 

Vijay  but second part is right which he will need to correct his existing posts   and he can use your tip from the next time 

Now, for once, Vijay is wrong (atleast I think so). 

Vijay, I do that all the time (copy pasting from MS Word-this is how I get the "proper" formatting for my posts), and I do not ever face such a scenario.

CK you are wrong! period

Vijay, check my blog. You'll get to know. I know this by experience. 

Double Period. 

CK You are wrong.  

I tested it now. If you add a highlight colour to text in word and paste it in blogger, then the highlight colour will also be copied.

Even I copy paste from word to preserve formatting ( paragraphs ( and biullet points etc ) ) 

triple period 

Ranjith, that is ought to happen. Blogger takes up the entire formatting from word, so, why not the text background colour?

I haven't ever put up the text background colour and then copy it in my blog.

What I was referring to was: 

you have copy pasted the text from the word document or other source.  This causes the white background behind the text.

And since the white background is in question, I don't expect a normal person to use a white text background on a white document background :P

Quadruple Period.

CK you are wrong I proposed, Ranjith seconded period period period 

now, let me check that white background thing 

I'm surprised that word allows 15 predetermined colours only for highlighting and white wasn't present in it. 

Vijay You are partially correct. adha marks dhe dhunga 

period Infinity 

Ranjith refer my reply below 

saw it 

Thank you Ranjith and Vijay.  Your suggestions have worked for me.  But I will not say whose suggestion worked for me I enjoyed reading your friendly conversation.  Thank you very much.

CK the OP had the specific problem with specific posts and that was due to copy paste.  The technical way out is here and of course here.

Now thank me 

The second link is nice  Thank you Vijay 

Welcome Ranjith 

Thanks, Vijay, Analyzing both the links for their merits.

Finally who is right   NSV should be a fair judge 

NSV you decide 

I'm weak in tech stuff but since Ranjith could not solve similar problem of mine, I'm deciding you as the winner

NSV I told you how to do it but you were lazy 

Thank You NSV

The solution you gave me was not smart. It was lke doing gadha mazdoori

LOL