1 Timothy 3:10 (NKJV)
Every product usually goes through some kind of testing before it is put on the market. No company that wants to be successful will just create something and start selling it before they know that it will actually work, that it will be a benefit to people, and that it will not harm anyone. This is a process that has been used for years by many companies to be sure that the products they want to sell will in fact be profitable. No company would be foolish enough to intentionally start trying to sell something that was not first tested; if they did the results would be disastrous.
This principle of testing something before it is ready to be used can also be seen in the Bible. When Paul wrote to Timothy about the kind of people who would serve as deacons, Paul told Timothy that these people first had to be tested and then they could serve, if they were found to be blameless. Paul was talking about deacons, someone who would do things like serve food. This would be the same kind of person that was talked about in Acts 6 where they looked for seven men of good reputation, who were full of the Holy Spirit, and wisdom. In 1 Timothy 3 and Acts 6 we see that both times they were looking for people who had already proven themselves.
When Paul wrote about elders, bishops, and deacons, he listed qualifications that those people needed to have before they could fill those positions. To know if they had the necessary qualifications those people had to be tested. Before we step into the things that God has planned for us there will also be a time of testing. This does not mean God will send sickness and problems to us, but with all of the things we are doing in our life, in our relationship with God, and in where we are already serving in our church, we are really being tested. God has good things in store for us, but to be ready and in the right position for those things we must first be tested and proven faithful.