They are gifts of grace, not merit, and so they are not at all indicative of a person's sanctification. They prove nothing but that God gives gifts freely. The next fact about spiritual gifts, then, is that they are services to be performed. Their primary function is for others. Gifts are for serving.
Spiritual gifts are also energizings.
It is likely that this word emphasizes the divine energy enabling us to perform the service. God gifts us to perform service in His strength. Spiritual gifts, then, are visible displays of service to others. Spiritual gifts are not abilities given to do something for yourself, alone. That is selfishness.