What is a blog?
A blog (a truncation of the expression “weblog”) is a discussion or informational website published on the World Wide Web consisting of discrete, often informal diary-style text entries (“posts”). Posts are typically displayed in reverse chronological order, so that the most recent post appears first, at the top of the web page. 
The term “weblog” was coined by Jorn Barger on 17 December 1997. The short form, “blog”, was coined by Peter Merholz, who jokingly broke the word weblog into the phrase we blog in the sidebar of his blog Peterme.com in April or May 1999. 
The emergence and growth of blogs in the late 1990s coincided with the advent of web publishing tools that facilitated the posting of content by non-technical users who did not have much experience with HTML or computer programming…. In the 2010s, the majority are interactive Web 2.0 websites, allowing visitors to leave online comments, and it is this interactivity that distinguishes them from other static websites. In that sense, blogging can be seen as a form of social networking service. Indeed, bloggers do not only produce content to post on their blogs, but also often build social relations with their readers and other bloggers. 
Exactly how many blogs there are in the world is difficult to know, but what’s clear is that blogs online number in the hundreds of millions. The total number of blogs on Tumblr, Squarespace, and WordPress alone equals over 440 million. In actuality, the total number of blogs in the world likely greatly exceeds this number. We do know that content is being consumed online more widely, more quickly, and more voraciously than ever before. According to WordPress, 76.3 million posts are published on WordPress each month, and more than 409 million people view 22.3 billion blog pages each month. 
U.S. President Barack Obama acknowledged the emerging influence of blogging upon society by saying “if the direction of the news is all blogosphere, all opinions, with no serious fact-checking, no serious attempts to put stories in context, then what you will end up getting is people shouting at each other across the void but not a lot of mutual understanding.” 
Blogging is self-publishing. One value that professional publishers provide is to bring readers to your work. One way they do this is to ensure that the work is quality work. They also find ways to monetize, or make money, from your work, which allows them to be paid and you to be paid. If you self-publish, that task falls to you … with the freedom to do everything your way and all of the money which is produced.
Who is your audience? What is your goal?
Could blogging help you influence your audience and reach your goal?
 Blog – From Wikipedia, the free encyclopedia at https://en.wikipedia.org/wiki/Blog
 HOW MANY BLOGS ARE THERE IN THE WORLD? from http://mediakix.com/2017/09/how-many-blogs-are-there-in-the-world/#gs.JzEcFGo
The image is from ChurchArt.com, a subscription service.