The Apostle Paul wrote these words to believers and they are Words for us today who believe.
They are spoken by the Spirit to Paul who wrote them down for the Ephesians and future believers and seekers to know the mind of God Almighty.
And the verses also explain clearly to a seeker of Truth, their spiritual situation before accepting the Gift of God - Salvation through Christ.
And you hath He made new, who were dead in trespasses and sins; where in times past you walked according to the course of this world, according to the prince of the power of the air (satan), the spirit that now works in the children of disobedience: among whom we also had our conversation in times past in the lusts of the flesh, fulfilling the desires of the flesh and of the mind; and were by nature the children of wrath, even as others.
But God, who is rich in Mercy, for His great Love wherewith He loved us, even when we were dead in sins, hath quickened us together with Christ, (by Grace we are saved) and hath raised us up together, and made us sit together in Heavenly places in Christ Jesus; that in the ages to come He might show the exceeding riches of His Grace in His Kindness toward us through Christ Jesus.
For by Grace we are saved through faith; and that not of ourselves: it is the Gift of God. Not of works lest any man should boast.