The Westminster Shorter Catechism
Q. 66. What is the reason annexed to the fifth commandment?
A. The reason annexed to the fifth commandment is a promise of long life and prosperity (as far as it shall serve for God's glory, and their own good) to all such as keep this commandment.
The Westminster Shorter Catechism in Modern English:
Q.66. What is the reason for the fifth commandment?
A. The reason for the fifth commandment is the promise of long life and prosperity, if these glorify God and are for the good of those who obey this commandment.
1. What type of "good" is this commandment speaking of, temporal or spiritual?
This commandment is speaking of temporal good, with a stipulation.
2. What is this stipulation?
The stipulation is that it must be to the glory of God. For the believer in Christ, whatever is good must be used for His glory.
3. What kind of temporal good is promised here?
The good promised here is long life and prosperity.
4. What is this "long life"?
It is not simply a matter of living long upon this earth but it is a long life of living for a reason - the glory of God. It is real living, living with a purpose and a blessing.
5. What kind of prosperity is promised?
The prosperity promised is a prosperity that must be seen within the framework of the glory of God. Sometimes it will be hard for the believer to understand how his lot might be called prosperity, but if through it God is glorified, it is for the believer's own good and some day he will understand why God took him through what the world would never label "prosperity".
6. Does this mean that all believers in Christ will have long life and prosperity?
No, only those believers who do not break this fifth commandment. Thy might find themselves in the position of the superior, or the inferior, or the equal. But whatever their position they must fulfil it as they should if they would receive the rewards spoken of here.
6. Why is the fifth commandment the first commandment with promise?
It is called this because it is the first commandment of the second table, and the only commandment in it that has a promise attached to it.