1 Corinthians 12:28 (NKJV)
Many countries in Europe use the Euro as their currency. One interesting thing about the Euro currency is that the bills are different sizes and colors. The larger the denomination, the larger the bill. For example, the 5 Euro bill is smaller than the 10 Euro bill, which is smaller than the 20 Euro bill, and so on. But if you had two 5 Euro bills and someone else had one 10 Euro bill these would be of an equal value. The person with the 10 Euro bill has one bill that is larger and a different color than the person who has the two 5 Euro bills, but they still have an equal value.
In 1 Corinthians 12, Paul talks about the Body of Christ, the Church. Paul explains how God has set different members, different parts into the Church. In 1 Corinthians 12:28 Paul gives a list of different parts of the church. This list is not necessarily completely inclusive because in places like Ephesians 4 we see other parts of the Church listed, evangelists for example. The thing that is really amazing is that it talks about all of these parts of the Church in the same context, showing that these things are of equal value.
Many Christians think that apostles and prophets are more spiritual or necessary to the Church than someone helping in the church or working in administration. Most people would not think that an usher, or the church secretary are as spiritual or necessary as a prophet, but God does! God has placed each believer in the Body of Christ to do a specific thing and each part is as valuable as any other, there are simply different functions. We all need to have the proper view of our value to God and understand that whatever God calls us to do is spiritual and necessary, no matter what others might think.