Genesis 1:31 And God saw every thing that he had made , and, behold, it was very good. And the evening and the morning were the sixth day.
Everything that God made is described as “very good”. This indicates the perfect nature of God’s creation. Sin had not entered the universe at this point. Adam and Eve are best thought of as “innocent”—they had the ability to sin, but had not done so yet.
There are some logical conclusions to this sinless state. First, physical death was not a possibility. Sin brought sickness, pain, suffering, and death as is seen in Genesis 3 and numerous other passages in the Bible.
Second, all animals and mankind were originally created as vegetarians. Animals and mankind were created with a spirit (Hebrew: nephesh). Since death was not possible, plants were food for nephesh creatures. See the article titled Food in Eden for more information on this topic. In addition, even accidental death was not possible in this “very good” world.
Third, there was harmony among God’s creatures. Animals were not killing and eating each other. Insects were not an annoyance, but rather a welcome part of the garden. There were no poisonous plants or ones which caused allergic reactions. All was well and at peace.
Fourth, God had communion with mankind. The relationship was not marred by sin. Adam and Eve had no reason to hide, nothing to deny, and every reason to love God and each other.
The sixth day ended and therefore the creation of the universe. Many doubt that God created everything in 6 days. This is due to the prevalence of evolutionary thinking. People have been conditioned to think in terms of long ages. However, God is not limited by our thinking. By His very nature, He can speak things into existence. He created this space-time universe we live in and did not require billions of years to do it. If one believes in the all-powerful, all-knowing, eternal, infinite God, then accepting that He could create everything in 6 days is not a stretch.