The Christian work ethic. It’s one of the reasons why Marxist liberal progressives hate Christianity:
Study Bible
2 Thessalonians 3:10
Warning against Irresponsibility
...9Not that we lack this right, but we wanted to offer ourselves as an example for you to imitate. 10For even while we were with you, we gave you this command: “If anyone is unwilling to work, he shall not eat.” 11Yet we hear that some of you are leading undisciplined lives and accomplishing nothing but being busybodies.…
http://biblehub.com/2_thessalonians/3-10.htm
Excellent point.