He told them (Gen. 2) they could take of all the fruits in the garden except the fruit of one tree, and if they disobeyed Him by eating the fruit of that tree, they should surely die.  God might have pointed out any tree, because it was simply a test of obedience.  He gave them a very simple command, for if we are faithful in little things we shall surely be faithful in greater.  Moreover, it is not precisely the consideration of what is forbidden, but of the authority by which it is forbidden that should deter us from violating the command and prove our fidelity.  Thus disobedience to our parents and superiors, even in little things, becomes sinful.  Someone might say:  “Why did God not try their obedience by one of the Ten Commandments?” Let us examine them.  “Remember the Sabbath.”  That one would be unnecessary:  for every day was Sabbath with them; the only work was to praise and serve God.  “Thou shalt not steal.”  They could not; everything was theirs; and so for the other Commandments.  Therefore, God gave them a simple command telling them:  If you obey, you and all your posterity will be happy; every wish will be gratified, neither sorrow nor affliction shall come upon you and you shall never die; but if, on the contrary, you disobey, countless evils, misery and death will be your punishment.  The earth, now so fruitful, shall bring forth no crops without cultivation, and after years of toil the dead bodies of yourselves and children must lie buried in its soil.  So having the gift of free will they could take their choice, and either keep His command and be happy, or disobey Him and be miserable.

42 Q. Which were the chief blessings intended for Adam and Eve, had they remained faithful to God?  A. The chief blessings intended for Adam and Eve, had they remained faithful to God, were a constant state of happiness in this life and everlasting glory in the next.

Our first parents and their children were not to remain in the garden of Paradise forever, but were, after spending their allotted time of trial or probation upon earth, to be taken body and soul into Heaven without being obliged to die.

43 Q. Did Adam and Eve remain faithful to God?  A. Adam and Eve did not remain faithful to God, but broke His commandment by eating the forbidden fruit.

As it is told in the Bible (Gen. 3), Eve went to the forbidden tree and was standing looking at it, when the devil came in the form of a serpent and, tempting, told her to take some of the fruit and eat.  It does not appear that she went and tasted the fruit of all the other trees and finally came to this one, but rather that she went directly to the forbidden tree first.  Do we not sometimes imitate Eve’s conduct?  As soon as we know a certain thing is forbidden we are more strongly tempted to try it.