@CK.. Trying to write an essay 
On Topic..
Yes, it is possible to make a living out of blogging.. Consider this your business so you have understand everything, each and every aspect..
Like BBA / MBA where they teach you things, or engineering, same goes for blogging also as its a vast field.. And too many parameter to fulfill..
Can a beginner do it ??
Lets see, a guys from Africa jungle, who knows nothing, arrives in Ahmadabad !!
So ?? No capital, no knowledge of anything ??
He would end up in service, perhaps delivering tea in a local tea store !!! 
If your level of beginning is that low, it would take you years before you gather up knowledge for the business you want to start.. Let alone the investment..
So, now what ??
Judge your self.. Where do you stand..
What is your level here in this industry ??
Can you afford that much time and money, since just like formal education and specialization, here too you have to invest learning.. Invest both money and time !!
How do all these people earn and makes their living ??
Simple and basic rule..
They have a website, where many people comes everyday.. Since many people comes, just like news paper, advertising companies or brands (directly) starts showing their advertisement and that generates the reveneu
Some also uses blog for other indirect income, like selling apps (hot field now a days), developing apps..
Here blog acts as a bridge !!
Always have a backup plan..
Maximum of the cases, things are heavily depended on Google.. For traffic and also income.. What if they blocks you, bans you.. What is your backup plan ??
Yes in many cases if you are good at this field, backup plan is itself another blog..
So, tell us, where do you stand ??
Ask you self these questions, since there is no easy money and time is the key, how much you can afford and invest, both in terms of long term time frame and money..