What events must occur before the start of the tribulation?

Matthew 24:14 says that the good news of the kingdom would be preached in all the inhabited earth for a witness to all the nations before the end comes. 1 Thessalonians 5:3 also tells us that there will also be a saying of “peace and security” before the Great Tribulation comes. Then there’s the final sealing of all the anointed ones here on earth in Revelation 7:3 that takes place before the Great Tribulation begins.