'Qualified' in the Bible

To some people we are a deadly fragrance, while to others we are a living fragrance. Who is qualified for this?

By ourselves we are not qualified to claim that anything comes from us. Rather, our credentials come from God,

who has also qualified us to be ministers of a new covenant, which is not written but spiritual, because the written text brings death, but the Spirit gives life.

For we rejoice whenever we are weak, but you are strong. And we pray for this: that you may become fully qualified.