The Fifth & Sixth Seals: Martyrs & Terror

The Fifth seal reveals the martyrs under the alter that cry out for God, who is holy and true, to bring about justice and avenge their deaths. Though they are told to rest awhile longer until all the martyrs have been gathered, when God does take action it will be an expression of His wrath against sinful man.
The Sixth seal brings terror on the earth as God shakes greatly the heavens and earth causing men to recognize the events are due to God's wrath and seek to hide from it. This seal concludes the "beginning of birth pangs" of the first part of the Tribulation period