Readers - 

This is something I have never seen happen. 

When looking at the verse First Thessalonians 4:17 to find the in-text value of Strong's Greek word 726 Harpazo (Caught up) I stumbled upon something that made me do a doubletake. "What was that?" I asked myself. 

The value of Harpazo in that verse = 518. 

I checked all the Bible words that have 518 as an in-text value here:

http://www.biblewheel.com/GR/GR_Database.php?Gem_Num=518

The first verse with a 518 valued word in it is Genesis 4:7, The word is DOOR

Genesis 4:7
"If thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the DOOR. And unto thee shall be his desire, and thou shalt rule over him".

Crossing number systems, the first verse with Strong's Hebrew word 518 (IF) in it is:

Genesis 4:7
"IF (518h) thou doest well, shalt thou not be accepted? and if thou doest not well, sin lieth at the door. And unto thee shall be his desire, and thou shalt rule over him".

yes, you're seeing double. It's exactly the same verse. 

Cain is getting held accountable by the Lord after murdering Abel, his brother. 

Cain is (imho) the first anti-Christ "type" in the Bible. He's a murderer and he is "marked" (by God). So, it makes sense that the reader lands there first using 1 Thess 4:17 (last days verse) as a starting point. 

Here's something else notable about 518. 

The first 518 VALUED word in the OT, is DOOR. 

The first 518 VALUED word in the NT is GATE. 

Jesus is Lord.