What is atheism?

Atheism is the view that there is no god. However, some atheists seek to define it as "having no belief in god". In this short video, philosopher William Lane Craig explains that the latter definition in flawed.

From my interactions with atheists, they often prefer the "having no belief in god" definition for a few reasons:
(1) on this definition, even babies are technically atheists, making it sound like it's the default position of human beings,
(2) it sounds like they're not being too rigid in deciding either way - they just don't happen to have that belief, like I don't happen to have blonde hair, and
(3) it means that they haven't had to do the hard work of grappling with the arguments for God's existence - they just 'lack belief' in God, in much the same way that I 'lack belief' in dragons.

The reality is, atheism - however they wish to define it - is an active position of the rejection of God.

The Apostle Paul got it right:

“The wrath of God is being revealed from heaven against all the godlessness and wickedness of people, who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.” (Romans 1:18-20; NIV)

Matt.