Sometime ago I had considered writing a post on this topic however yesterday morning I read a very insightful chapter in "The Purpose Driven Life" by Rick Warren that addressed this issue perfectly, so I will adopt that work as the main basis for this week's thought (aka TFTW). Today I will present Part 1 which will look at the "why" at times God will seem distant. Next week for Part 2, we'll cover the "what we should do" when it happens.
To be honest, the "why" is all broken down into a single core point.
Separation is vital for the development of our faith. To mature in our friendship with God, He will test it with periods of seeming separation - times when it feels as if He has abandoned or forgotten us.
As Rick notes, "When you are a baby Christian, God gives you a lot of confirming emotions and often answers the most immature, self-centered prayers - so you'll know he exists. But as you grow in faith, he will wean you of these dependencies." Moving on from this, our God is concerned with one main question; "Will you continue to love, trust, obey and worship God, even when you have no sense of his presence or visible evidence of his work in your life?" This is a key question to determine our spiritual maturity.
Here it is important to consider that you are not the only one being tested, even if when you look at fellow Christians, all seems well in their lives. No no, don't think you are alone at all, we all are tested! From those just passing that 'baby Christian' phase to those who are far along in the Christian path. If we reflect on the Bible, we see examples of the latter in both David and Job. Surely everyone remembers the story of Job, but even David - probably one of the closest to God - struggled: "Yet David frequently complained of God's apparent absence: 'Lord, why are you standing aloof and far away? Why do you hide when I need you the most?'[1] 'Why have you forsaken me? Why do you remain so distant? Why do you ignore my cries for help?'[2] 'Why have you abandoned me?'[3]"
But we know as did David, that God would never leave us or forsake us [4,5] so WHY does He seem so distant?! My brothers and sisters in Christ, it is all for the development of our faith. The email signature of one of my friends comes to mind as it notes, "The gem cannot be polished without friction, nor man perfected without trials". The Biblical - and likely original - version of this phrase can be found in James 1:2-4, as it states, "My brethren, count it all joy when you fall into various trials, knowing that the testing of your faith produces patience. But let patience have its perfect work, that you may be perfect and complete, lacking nothing". How true is that!
So, it's all about our development and maturity, all about the edification of that relationship with our God. When faced with trials myself, and not knowing where to go, or what to do, I often remark, "God knows what's best for me, much much better than I do anyway!" Therefore, let's just keep loving, obeying, worshipping and trusting Him to direct us and carry us!
Have a great week and Lord willing, we will continue this discussion next time with Part 2. 
Update: Here's the link to Part 2!