The health of Lazarus had got worse and needed urgent action. Mary and Martha were in dire need of the LORD's swift intervention. A message had been delivered to Jesus informing Him of the severity of Lazarus' sickness but the only reply He gave was "this sickness is not unto death..."
This might had sounded as an assurance to the two sisters that their brother was not going to die. I'm sure that they also expected and waited for the LORD to arrive quickly and heal him, but to no avail.
John 11:1-4 KJV
"Now a certain man was sick, named Lazarus, of Bethany, the town of Mary and her sister Martha.  (It was that Mary which anointed the Lord with ointment, and wiped his feet with her hair, whose brother Lazarus was sick.)  Therefore his sisters sent unto him, saying, Lord, behold, he whom thou lovest is sick.  When Jesus heard that, he said, This sickness is not unto death, but for the glory of God, that the Son of God might be glorified thereby.
It is safe to say that Mary and Martha already found themselves in what we can call a dead situation when Lazarus gave up the ghost. I could imagine how they felt when the LORD didn't show up according to their expectation. Their faith couldn't help their feet anymore and they collapsed to the floor weeping uncontrollably. They had no option than to lay their brother to rest.
Some times we happen to find ourselves in the same shoes as Mary and Martha; situations that makes it very difficult to keep believing and trusting God for a solution. We've had problems that are so serious to the extent we question whether we'll survive it.
I've personally been there. I've been hit by problems that sucked out my strength and the only prayer I could pray was "LORD help me". It doesn't mean we don't have faith, but even when we're faithless, God remains faithful. The LORD takes pleasure in proving Himself faithful when all hope is lost. That is one of the things that makes Him remain the God whose ways defy man's understanding.
Some of us have been through things that are worse than sicknesses. Job's case was a good example. I can imagine how bad it was, to the extent his wife saw no need for him to continue living.
DEAD SITUATIONS AND WHY GOD ALLOWS THEM
Dead situations are situations that our faith often possibly can't withstand. At the valley of dry bones, when God asked Prophet Ezekiel, "Son of man, can these bones live?", that was a really tough question. But Ezekiel being smart enough wasn't gonna say, "Sir, it's hard for me to see that happening". Instead he said, "thou knowest".
Ezekiel 37:3 KJV
And he said unto me, Son of man, can these bones live? And I answered, O Lord God, thou knowest.
Unless you've never encountered things that did shake your faith before you can say that Ezekiel would had given a straight-away "Yes" as an answer. Dead situations are those which only God knows the outcome. He alone knows He can provide a solution to them.
The LORD may allow us go through such for the following reasons:
1). To Make Us Dependent On Him: Some of us may have enough to make us self-sufficient and that is like pride and rebellion against God. God is good at humbling the proud so as to save their soul from destruction.
He can allow us go through things that will make us lose dependence on our abilities, everything we've had and arm of flesh. Our sufficiency must be in God and nothing else.
2). To Build Our Faith And Trust In Him: When the LORD delivers us from situations or problems we never thought we'll get out of, it builds our faith. The faith of Mary, Martha and Job could never remain at the same level after God had delivered them from such disasters.
3). To Glorify Himself In It: The LORD's further response to Mary and Martha was that Lazarus' sickness was for His Glory. If people do not go through things no man can provide a solution to, how will God get the glory?
The LORD may allow us go through things that will make people write us off. He is good at surprising those who wrote us off during our season of going through. At the end of the day we can not boast that by our own strength we went through Hell and came out unharmed. God gets the glory.
LIGHT AT THE END OF THE TUNNEL
The LORD is mighty to save. He is a Mighty Restorer. He gives back life to what we concluded was dead and could never get better. Job found himself in a situation that made people write him off. Even his wife was like, "Man! this your God though... you're not gonna come out of this. Why not just curse Him and die?". Even Job's faith was shaken.
But God is not a man. How can mere mortals understand His ways? You may feel helpless and hopeless in that present situation, but trust Him because there is light at the end of the tunnel.
Psalm 91:9-10 KJV
Because thou hast made the Lord, which is my refuge, even the most High, thy habitation;  There shall no evil befall thee, neither shall any plague come nigh thy dwelling.
The LORD saying that no evil shall befall us doesn't mean He won't allow us go through. Peter was already sinking in the sea when He gave out a helping hand. He said that when we go through the fire, He will be with us.
That sickness is surely not unto death. God may not always intervene according to our specification and expectations. But hold on, because He is about to do a miracle. He will step in when you least expect and bring a radical turn-around that will leave you and many others in awe!
Psalm 30:5 ...weeping may endure for a night but joy comes in the morning.
I can't personally recount every situation the LORD saw me through and keeps on doing so. They're just very many. He is a good Father and we can only get the best from His hands.
Your faith may not be strong enough to sustain you through hard times, but hold on to your trust in God. Even Job's faith was shaken, but he refused to let go of the hem of the LORD's garment.
A double portion restoration is coming to everything you might had lost. God is in the business of surprising those who hold unto Him no matter what they've been through.
Great Grace and God's strength to go through I declare upon you who is reading this article. Never forget that the LORD is with you through it all. Keep praying, keep trusting Him, and He will hold your hand and take you out of it. Amen.
Stay Pure, by His Grace. Remain Blessed.