Use of the phrase "God's children" could refer to several different groups; for instance, all of mankind, the nation of Israel, all those who consider themselves Christian, and the little flock of people who have followed Jesus in dedicating their lives in sacrifice to God (Romans 12:1).

The world of mankind is living out the punishment given to Adam and all his posterity for his original sin: "In the sweat of your brow you shall earn your food, till you return to the ground from which you were taken; for dust you are, and you return to dust." Genesis 3:19 (Amplified Bible)

Israel, though God's chosen people ("Happy the nation whose God is the eternal, the people He has chosen for His own."  Psalm 33:12  Moffatt), was punished for continuous disobedience involving the worshipping of idols. However, their punishment is over, as is witnessed by the regathering of the Jews to their own country. "And they will know that I, Yahweh, am their God, when I have carried them into exile among the nations, and shall then gather them upon their own soil…. Neither will I any more hide my face from them, in that I have poured out my spirit upon the house of Israel."  Ezekiel 39:29, 30 (Rotherham translation)

Professed Christians who attend church on Sunday, but who otherwise live lives as the general population does, are hypocrites in the eyes of the Lord and receive their only reward now in the admiration of others.  "Verily I say unto you, they have their reward."  (Matthew 6:16) If they remain in the church system, they will receive of her punishment. "Come out  of her, my people, so that you may not share in her sins,  neither participate in her plagues." (Revelation 18:14 Amplified)

God's special people have dedicated themselves to a life of sacrifice.  Paul attested, "Thrice was I beaten with rods, once I was stoned, thrice I suffered shipwreck, a night and a day I have been in the deep." (II Corinthians 12:25) Concerning trials, James said, "Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance. Perseverance must finish its work, so that you may be mature and complete, not lacking anything." James 1:2-4  NIV The reward for the overcoming of such trials:  "Be thou faithful unto death, and I will give thee a crown of life." Revelation 2:10 

"Blessed are you when men denounce you and persecute you and utter all manner of evil against you for my sake; rejoice and exult in it, for your reward is rich in heaven; that is how they persecuted the prophets."  Matthew 5:11, 12 Moffatt

The last scripture teaches that the world will hate true Christians. Why? John 3:20, “Everyone who does evil hates the light, and will not come into the light for fear that their deeds will be exposed.” Truth and righteousness expose sin, and people don’t want their sins revealed. So, they try to snuff the light by humiliating and persecuting Christians.

We look forward to the time when “They shall not hurt or destroy in all my holy mountain; for the earth shall be full of the knowledge of the LORD as the waters cover the sea.” Isaiah 11:9