Endings always bring new beginnings. Satan strives to keep us out of the new place that God has prepared. He wants to trap us in the past and causes us to live in permanent misery. Self-anger and self-blame will accomplish the devil's purpose.
People may also experience anger at the person who left them—even if they died. My aunt told me that after my uncle died, she would sometimes beat his pillow at night and yell, "Why did you leave me?" Obviously, her intellect knew that he did not purposely leave her, but her emotions were speaking. We must realize that emotions have a voice; and when they are wounded, they may react like a wounded animal. Wounded animals can be quite dangerous, and so can wounded emotions be, if they are followed.
The grieving person needs to be taught about this grieving process and some of the things he may experience. He must also be taught to place little or no value on his feelings—and not to follow them. For a person who has experienced a major loss, it is not the time to be making serious decisions nor the time to deal with other issues that may be anxiety producing or emotionally upsetting.
Anger at God is quite common. People frequently ask, "If God is good, all powerful, and full of love for us, why didn't He stop the thing that caused the pain?" Satan seeks to build a wall between God and the hurting person. He seizes the opportunity to say, "God is not good, and He cannot be trusted." However, we know that it is a lie. Satan is a liar and the father of lies. The truth is not in him according to the Word of God.
Verses 12 and 13 of James 1 states, Blessed (happy, to be envied) is the man who is patient under trial and stands up under temptation, for when he has stood the test and been approved, he will receive [the victor's] crown of life which God has promised to those who love Him. Let no one say when he is tempted, I am tempted from God; for God is incapable of being tempted by [what is] evil and He Himself tempts no one.
And verse 17 says, Every good gift and every perfect (free, large, full) gift is from above; it comes down from the Father of all [that gives] light, in [the shining of] Whom there can be no variation [rising or setting] or shadow cast by His turning [as in an eclipse].
In other words, God is good; and He cannot be anything else. Furthermore, He is not one way one time and another way another time. He does not change. He is good, and that is the way He is. But what about the original question? Since God is good and all-powerful, why didn't He stop this thing before it brought all the hurt and pain?
To be very honest, these are questions for which we do not have completely sufficient answers.
I Corinthians 13:12 says, ...Now I know in part (imperfectly)... Trust always requires unanswered questions!
We want answers to everything, but we must come to the place where we are satisfied to know the One who knows and place our trust in Him. Being mad at God is foolish because He is the only One who can bring the needed help and comfort to the grieving or bereaved person.
Finally, people also get angry at the devil. This is normal and even good if the anger is properly expressed. The only way to repay the devil for hurt and devastation in our personal lives is to aggressively and vehemently do the works of Jesus. I receive much comfort and joy from Romans 12:21, ...overcome (master) evil with good.
People experiencing tragedy often go through stages of emotions expressed as sobbing and hysteria. These may come and go when least expected. Even people who are normally quite unemotional may experience a great deal of emotion during times of loss.
In general, people are afraid of emotions; and an uncontrolled display of these emotions is even more fearful. I encourage you to "fear not" because it will pass. Good understanding and a lot of help from the Holy Spirit will bring you through this kind of situation.
Confusion, disorientation, and fear are common. Depression and waves of overwhelming feelings are experienced by many, as well as, physical symptoms caused by the emotional stress, with which the wounded person is dealing. I believe the key word in these situations is balance.
The Bible talks of how King David was feeling depressed, but he resisted it. He did not sink into it, nor get into the pit of despair. He described how he felt, but he made a decision not to live by his feelings (read Psalm 42:5-11 and Psalm 143). People have often confided to me their discouragement from being made to feel (by others) that they had insufficient faith when they go through experiences like this.
I believe it often takes more faith to go through something victoriously than to be delivered from it. There are some that experience complete deliverance from grief after a great loss, but that does not happen to all people. There are others, and I might even say most of us, who go through very emotionally difficult times when tragic loss occurs. Those who are walking in faith come out of it, and they come out of it better than when they went in. In closing, let me say, "Do not lose your hope!" If you are hurting right now due to a loss in your life, I want to say to you that a new beginning is in front of you. You may go through some things that you will never understand, but you can trust God to work them out for your good. What Satan intends for your harm, God can turn around for your good!