"When he opened the second seal, I heard the second living creature call out, “Come!” And out came another horse, bright red; its rider was permitted to take peace from the earth, so that people would slaughter one another; and he was given a great sword."
The writer at Bibleref.com interprets the red color of this horse to mean blood, denoting a time of war and great civil unrest, and also connects the Greek translation of the term 'great sword' with a reference to a specific kind of Roman weapon. This is a suggestion that this verse might refer to an aspect of Roman history (or not, John of Patmos might just be using terminology the reader at the time of his writing would have been familiar with).
It's important to note that the rider only comes when beckoned by one of the living creatures described in earlier verses. This makes it clear that all this is being done, or allowed to happen, under God's command, not by the will of mankind.
The writer of the above article also says that this scale of slaughter rules out the first rider on the white horse being Christ, and some interpreters go even further with the identity of the first rider, implying that this rider might in fact symbolize the anti-Christ.
If you want to accept Salvation from Christ here are some resources:
A Prayer for Salvation from Christ:
Lord Jesus, I confess my sins and ask for your forgiveness. Please come into my heart as my Lord and Savior. Take complete control of my life and help me to walk in Your footsteps daily by the power of the Holy Spirit. Thank you Lord for saving me and for answering my prayer.
A more detailed step by step process:
https://www.wikihow.com/Accept-Jesus-Into-Your-Life
