God is amazing. As we progress through the Christmas season (not the holiday season), we get swept up in the love of God. God loves us, that's why He sent His Son, Jesus. Every Christmas families gather together and hear the story of the Messiah's birth. Christmas is a time for celebration for those who know and have a personal relationship with Jesus. It's like a birthday party for your best friend. But for those who don't know Him, God isn't a good thing. The return of the King will not be a time of joy for those who choose not to follow Him.
Christians talk about the rapture fairly often. God is coming back. It could be any time, only the Father knows when. When He does, we will return to Heaven alongside our Savior and King. But for those who don't know Him, it's will be a terrible, awesome thing. 7 years of tribulations await everyone who is left behind. God will give control of the world over to the Antichrist and Satan himself. Many will be deceived into following the Antichrist and directly disobeying God's commands.
Many will die. We see a few times in scriptures; God loves us, but His wrath is a terrible, terrible thing. When God takes His people home, we're getting the hell out of Dodge. But those who have been introduced to Him are condemned without knowing what they did wrong. There aren't plenty of prophecies about the End times, and they aren't good.
Me and my friends are reading Joel right now, and it seems to prophecy about the end. Joel speaks of fire, locusts, barren land. Not a good time. The people will weep and cry and there will be gnashing of teeth. It is described as both awesome and terrible, and both descriptions are accurate. The destruction will be terrible, God's really gonna get his money's worth. But the power of God and his ability to strike in such an incredible way is truly awesome.
Christmas has such a focus on gifts and commercialism, that the focus is less on God than ever before. And I'm not even saying that the focus should be on glorifying God. We should always seek to glorify God. But Christmas is the perfect time to share the Gospel with non-believers, seeing how the holiday is the birthday of our Lord. Don't just tell the story of His birth. He was born to die; tell the other end of His story. Jesus was God-incarnate, born to die as a sacrifice for the sin of all mankind. Make sure people recognize that, because there will be a time when it's too late to save people from a terrible, yet awesome fate