Jesus had just received the message that His friend, Lazarus, was seriously unwell (John 11:1-3).  Instead of showing anxiety, as we might have done, He simply responds that God would be glorified.  The end of the story would not be his death, but that all would see that Jesus really was God's Son.  He was not at all callous or indifferent to the suffering of Lazarus, or the anxiety Martha and Mary were experiencing, but He knew it was important not to answer their call immediately.  We know from the narrative that Lazarus did die, probably about the time when Jesus received the message, and yet Jesus remained miles away for two more days.
 
In many cultures, care is shown by immediate action, and any delay is a sign of indifference.  But Jesus knew it was essential that He did not react immediately: it was necessary for Lazarus to be undeniably dead for four days before Jesus miraculously gave him new life (John 11:39).  This would demonstrate God's power to raise the dead; and to prepare His followers for His own God-authorised resurrection.  

But the narrative makes plain that although He deeply loved the family and was grieved at their distress (John 11:33-36), it was essential for them to go through the ordeal of bereavement so that they might experience Jesus' ability to defeat Satan's power over death and liberate those who are bound by their anxiety about death (Hebrews 2:14-15).
 
Our anxious hearts often tremble when God delays His answer.  But we should not fear.  He always knows every circumstance.  He deeply loves those who suffer, and He also has a higher purpose than simply resolving our problems.  For if our troubles were solved the moment we cried, we would not need to develop faith … we might think that God was at our command allowing us to claim glory for ourselves.  Whereas it is most important that Jesus is glorified - because only then will we be truly satisfied.  Neither should we interpret God's delay as disinterest, but rather use the time gap to grow in faith.  The testing of our faith is essential if we are to mature as believers (1 Peter 1:3-9).  So do not be discouraged when prayers do not seem to be answered.  God knows what He is doing in our circumstances and in our hearts – so that we will be able to respond in joy as God’s answers are revealed and Jesus will be glorified.