You can't fit a square peg in a round hole

You can't fit a square peg in a round hole - so the saying goes.  And it is true.  You can try.  And you may sort of get it to fit.  But there will be gaps round the edges.  If you pour some water over it, you'll soon see the peg may be in, but the hole isn't plugged! You need a round peg for a round hole.  And come to think of it, you need the right size of round peg, to perfectly fit a round hole. With this in mind, we come to the next question in the catechism.

Q21.  What sort of Redeemer is needed to bring us back to God?

A. One who is truly human and also truly God.

This might seem like an odd question.  You may have never thought of it before.  So why do we need to consider this question? It's about square pegs and round holes.  If you have a hole that needs plugged, you need the right peg.  We have a problem with sin, and we need the right Redeemer to deal with that problem.  This is not the case of any one will do.  We need a Redeemer who is both truly human and truly God. The next questions will explore more about

why

 this is the case.  For now, lets note one thing - sin is

our

problem.  And because it is OUR problem, it takes one of

US

to solve it.  A real human being.  Not a robot.  Or an angel.  Or even God alone.  It takes one of us.  A human being. Now, no human being is capable of doing this.  We have all been so corrupted by the fall.  That is why the Son of God, himself, came.  He took on flesh.  He came as a true human.  He live a perfect life.  And he stands as our representative.  Our head.  Our saviour.  Our Redeemer.