The second seal is the repetition of the Church of Smyrna in more detail.
The Smyrna church is during this period. There are several references to death in the message meant for Smyrna's church. Jesus revealed Himself to this church as "the one who was dead and is alive eternally" (Revelation 2:8). Jesus exhorted Smyrna's citizens to remain loyal unto death (Revelation 2:10). He said they would not suffer from the second death (Revelation 2:11). Smyrna's 10 days represent the ten years of Diocletian persecution, from 303 to 313 A.D.
Revelation Chapter 6 - Verse 3 to 4
3 And when he had opened the second seal, I heard the second beast say, Come and see.
4 And there went out another horse that was red: and power was given to him that sat thereon to take peace from the earth, and that they should kill one another: and there was given unto him a great sword.
According to the Bible, the color red is associated with bloodshed. When the sword removes peace from the land, conflict and slaughter follow afterwards (Isaiah 63:2; Nahum 2:3; Revelation 17:1-6).
The Sword symbolizes the Bible:
Ephesians 6:17 - “And take the helmet of salvation, and the sword of the Spirit, which is the word of God.”
The gospel offers peace to those who accept it.
Ephesians 6:15 - "And your feet shod with the preparation of the gospel of peace"
Question:
At this point, the most important question is why, if the Sword is the Bible, then why does it take away peace?
Answer:
When sinners listen to the Bible's message, they find inner peace.
When sinners reject its message, they rise up and steal the preachers' peace. In other words, the Sword of the Spirit (Hebrews 4:12, 13) delivers a sword of persecution to those who reject it.
The first horse's triumphs led to persecution by the second horse. Satan, alarmed by the enormous number of people leaving his army (Revelation 2:10), launched a brutal persecution against those who were capturing subjects for his kingdom through the proclamation of the gospel.
The key text to explain the meaning of the Sword in the second seal is Matthew 10:34-39. These verses contain the same three words that appear in the second seal: earth, peace, and Sword.
Matthew 10:34-39 - “34 Think not that I am come to send peace on earth: I came not to send peace, but a sword.
35 For I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law.
36 And a man's foes shall be they of his own household.
37 He that loveth father or mother more than me is not worthy of me: and he that loveth son or daughter more than me is not worthy of me.
38 And he that taketh not his cross, and followeth after me, is not worthy of me.
39 He that findeth his life shall lose it: and he that loseth his life for my sake shall find it.”
However, Satan's attempts to destroy the Church of Christ by violence (the red horse) were in vain.