The Bible talks about getting your ear pierced. Exodus 21 :6 says that a slave who wanted to dedicate his life to his master would : "go to the doorpost...and his master shall pierce his ear with an awl...and he shall serve him permanently."
There's a phrase used in greek : "doulos"...and it means bondservant. Paul applies that term to himself in Romans 1. It gives the idea of total allegiance not just isolated acts of service ( worship). I like that idea, but I am reluctant to go to the doorpost sometimes. Do I really want to give my total allegiance ? Have I really thought through how that will effect my money, time, "free time" ? What if I don't go to the doorpost ? Am I leaving myself a way out of total allegiance ?