One of the many jobs of parenting is to help your kids mature as they grow up.  As children get older, their maturity level is supposed to keep in step.  A ten year old is to act like a ten year old or older.  A ten year old is not to act like a two year old.  When kids get to the age of an adult they are to act like adults.  This is easier said than done!  This maturity process is also expected in the Christian life.  When one accepts Christ, spiritually speaking, that person is a newborn baby.  But with time every Christian is supposed to grow to be more spiritually mature.