I once heard an interesting quote, and you'll have to forgive me as I don't remember the source, but the quote went something like this.  "Men build islands, but God builds Arks.  Which will you chose for your safety?"  The idea that statement conveys is monumental.  But to understand it you first have to understand the key differences between the two that make this quote powerful, despite its tiny size.  First off, let's look at the characteristics of each item.  An island is large, immobile, solid, and generally immovable.  An ark is small (typically) in comparison, mobile, driven by wind and waves, and often lacking any means to keep it in one place for any length of time.  An island is typically capable of providing all that its inhabitants need.  An ark is dependent on benevolent forces beyond itself for its supply.  An island holds many people.  An ark (aka, a boat) often holds few.  Now, let's look at these two from a biblical standpoint.

If an army approaches you and wishes to attack you, an island is actually a disadvantage to your safety.  For one it's stationary, as mentioned above.  That means that when the danger comes you can't escape.  With an ark, or a boat for that matter, you can usually flee from danger.  An island is easy to see, and many can easily find it.  A boat is often hard to find and can easily be hidden.  An island is difficult to defend.  A boat however is easy to defend as it has its own natural moat so to speak.  A boat can go where it wills.  An island can't.  If the waters rise you can climb higher on an island for safety.  But after a certain point you run out of land and can't go any higher, shortly after which you drown.  However, with a boat or an ark, since it floats on the water, the higher the water rises, the higher you rise since it floats on top of the water!

The idea of trusting in solid land masses (spiritually and physically speaking) is foolish.  Just look at the incredible losses and defeats suffered by the Japanese during World War 2.  Although the island can provide all you need, those resources are subject to destruction and capture.  With a boat one must capture the vessel in order to deny its passengers access to the cargo, or deny one's benefactor from resupplying it.  And I'm just lightly touching on this.  There's so much more to this and this little quote is so deep I can't even begin to scratch the surface of its potential message to anyone who reads it.

Also, if we were to look at the bible for further examples, a simple glance through Genesis will give us a great one to chew on.  Look at the story of Noah.  What does God build?  And what happens to those outside the ark?  Or what about the fishermen who became the apostles of Christ?  What did Jesus quite often do?  Yes, He put them in boats, partially because that was the best mode of travel, and partially because they were fishermen and thus would own their own.  Even Jesus was an ark Himself, albeit spiritual rather than physical.  So if you look at the larger picture, the boat in the bible is a symbol of safety.  How so?  Well, think about it.  Have you ever tried to walk from one side of a lake to the other through the middle?  What usually happened when you did?

Well, aside from getting soaking wet, after a certain point you were likely forced to swim, and if the lake is wide enough you'll end up drowning.  Especially if there's a storm.  And even if you don't drown, how can you take anything with you?  Ah, that's just it!  You can't!  You need a boat to take with you anything more than yourself, a minimum of clothing, and do it without getting soaking wet!  God used an ark to save mankind and all living creatures alive (through a representative group of animals) through the great flood.  Man in turn has tried to use islands many times in the past for safety and failed.  Yet God has never failed.  So with that in mind, go re-read that quote and think about it today.  Which will you choose?  Man's island, or God's ark?