The answer is, “Creation is God’s making everything out of nothing by His powerful word in six days – and all very good.”
It is probable that most people that read this question in the catechism in 2016 zoom in on the words “in six days.” So let me say from the beginning that it is OK for believers to disagree on how the word day should be interpreted. Some hold to a literal 24 hour day and others think day represents a much longer period of time.
How I interpret the word day in Genesis 1 is not going to cause me to break fellowship with other believers who take an alternative view. The one thing on which Christians should agree is that God is the cause for the world in which we live. God created it and we are his creatures.
At then end of Genesis 1, it says that God was satisfied with what he created, he declared that it was all “very good” (Genesis 1:31). Even though we have marred creation through rebellion, it still carries the marks of intrinsic goodness and creativity. God is a very gifted artist.
Take any category of plants or animals and look at the variety within that category. God didn’t make one kind of dog or one kind of fish or kind of bird. In each of these animals, there is incredible diversity. At my bird feeder we get such a variety of birds; chickadees, sparrows, nuthatches, finches, woodpeckers, jays, doves, cardinals and blackbirds are regular visitors.
Why did God build such variety into his creation? I believe it is to delight man, his highest creation. The variety is a clue as to how much God loves us.
At present we see the goodness of creation though it carries the scars caused by man’s failure to obey. But Jesus has promised to one day return and set it all right again. One day the taint will be removed and we will see the universe how it was meant to be.
In that day, we will then say with God that it is “all very good.”