God’s guarantee begins with the introduction: “The One seated on the throne said.” (Rev. 21:5a) These words introduce one of only three instances in the book of Revelation when Jehovah speaks in the visions. So this guarantee is provided, not by a powerful angel, not even by the resurrected Jesus, but by Jehovah himself! This fact highlights the trustworthiness of the words that follow. Why is that so? Because Jehovah “cannot lie.” (Titus 1:2) That statement makes the words that we read at Revelation 21:5, 6 completely reliable. Consider the word “Look!” The Greek term translated “look!” is used repeatedly in the book of Revelation. What follows the exclamation? God’s statement: “I am making all things new.” True, Jehovah is speaking about future changes, but for him this promise is so certain to come true that he speaks of these changes as if they were already taking place.​—Isa. 46:10. w23.11 3-4 ¶7-8

The apostle Peter struggled with his weaknesses. Consider a few examples. When Jesus explained how he would suffer and die in fulfillment of Bible prophecy, Peter rebuked him. (Mark 8:31-33) Repeatedly, Peter and the other apostles argued about who was the greatest. (Mark 9:33, 34) On the last night before Jesus’ death, Peter impulsively cut off a man’s ear. (John 18:10) That same night, Peter gave in to fear and three times denied knowing his friend Jesus. (Mark 14:66-72) That led Peter to weep bitterly. Jesus did not give up on his disheartened apostle. After Jesus was resurrected, he gave Peter the opportunity to reaffirm his love for him. Jesus invited Peter to serve humbly as a shepherd of his sheep. (John 21:15-17) Peter responded positively. He was in Jerusalem on the day of Pentecost and among the first to be anointed by holy spirit. w23.09 22 ¶6-7

“Shepherd the flock of God,” the apostle Peter urged his fellow elders. (1 Pet. 5:1-4) If you are an elder, we know that you love your brothers and sisters and want to shepherd them. However, you may at times feel that you are so busy or so tired that you cannot fulfill that assignment. What can you do? Pour out your concerns to Jehovah. Peter wrote: “If anyone ministers, let him do so as depending on the strength that God supplies.” (1 Pet. 4:11) Your brothers and sisters may be facing problems that cannot be fully solved in this system of things. But remember that “the chief shepherd,” Jesus Christ, can help them beyond what you can do. He can do so both today and in the new world. God asks elders simply to love their brothers, to shepherd their brothers, and to become “examples to the flock.” w23.09 29-30 ¶13-14