What happens if you decide to discover, develop and use your spiritual gift or gifts?

Several things.
First of all, you will be a better Christian and better able to allow God to make your life count for Him. People who know their gifts have a handle on their “spiritual job description,” so to speak. They find their place in the church with more ease. I have often said, half in jest, that one immediate benefit of the people in a church knowing their spiritual gifts is that the nominating committee can be phased out and a screening committee set up to receive applications for work. But it is happening. A few months ago I received a letter from Pastor Paul Erickson of First Covenant Church of Portland, Oregon, who had been studying church growth in the Fuller Doctor of Ministry program. His letter said, “Our people have joined the exciting search for discovering and using their spiritual gifts. Six of our people contacted the nominating committee for service on the boards next year!”
My church, Lake Avenue Congregational Church, still has a nominating committee. But when they submit their annual nominations to the congregation, each nominee has a brief bio, and the first item specifically lists their spiritual gifts. We hope no one occupies a position in our church who is not gifted by God for that particular responsibility.
Christian people who know their spiritual gifts tend to develop healthy self-esteem. This does not mean they “think more highly of themselves than they ought to think.” They learn that no matter what their gift is, they are important to God and to the Body. The ear learns not to say, “because I am not an eye, I am not of the body” (1 Cor. 12:16). Crippling inferiority complexes drop by the wayside when people begin to “think soberly of themselves.”
Humility is a Christian virtue, but like many good things it can be overdone. Some Christians are so humble they render themselves virtually useless to the Body. This is a false humility, and it is often stimulated by ignorance of spiritual gifts.
People who refuse to name their spiritual gift on the grounds that they would be arrogant and presumptuous, only exhibit their failure to understand the biblical teaching on gifts. Some may have a less noble motive for not wanting to be associated with a gift—they might not want to be held accountable for its use. In that case, humility can be used as a cover-up for disobedience.
Most people who know their spiritual gifts and are using them are not bogged down by such negative attitudes. They first of all love God, they love their brothers and sisters and they love themselves for what God has made them to be. They are not proud of their gifts but they are thankful for them. They work together with other members of the Body in harmony and effectiveness.
Second, not only does knowing about spiritual gifts help individual Christians, but it also helps the Church as a whole. Ephes. 4 tells us that when spiritual gifts are in operation, the whole Body matures. It helps the Body to gain “the measure of the stature of the fullness of Christ” (Ephes. 4:13).
When the church matures, predictably it grows. When the Body is functioning well and “each separate part works as it should, the whole body grows” (Ephes. 4:16, TEV). Clearly, a biblical relationship between spiritual gifts and church growth exists. This whole book is intended to be an elaboration of how this relationship can work in practice.
The third and most important thing that knowing about spiritual gifts does is that it glorifies God. 1 Peter 4:10-11 advises Christians to use their spiritual gifts, then adds the reason why: “That in all things God may be glorified through Jesus Christ, to whom belong the glory and the dominion forever and ever. Amen.” What could be better than glorifying God? It is the “chief end of humans,” according to the Westminster Catechism.Your Spiritual Gifts Can Help Your Church Grow.