Consider these powerful words from Walter Marshall:
You might think that because non-Christians are lost in sin, and unable to obey God, it is useless to preach the Gospel to them. This is not so! It is not useless to preach the Gospel to non-Christians, and call them to repentance and faith in Christ. You preach the Gospel to non-Christians so they will be converted to Christ and saved.
The goal of preaching to non-Christians is not to enable them to come to holiness while they remain in their old nature. The goal is to raise them above their natural state, to present them “perfect in Christ” (Col. 1:28)- not in themselves.
To be sure, they cannot live holy lives while they remain in their natural state. However, the Gospel is the power of God for their conversion and salvation, by the power of the Holy Spirit.
When the Gospel is preached, the Holy Spirit works in people.
He gives life to those who are dead in sin, and He makes them new creations in Christ. He gives people repentance unto life, and he gives them true faith in Christ. The Gospel comes to those who are elect by God, not “only in word, but also in power, and in the Holy Spirit,” and in such assurance that they “receive it with joy in the Holy Spirit (II Thessalonians 1:5-6). “The Gospel is the ministry of the Spirit, who gives life” (II Corinthians 3:6-8). The Gospel is “mighty because of God” (II Corinthians 10:4).
The Gospel does not depend at all upon the power of your own free will to successfully convert you and bring you to Christ.
The Gospel gives life to your soul, and it gives you the power to receive it and obey it.
Christ makes those who are dead in sin to “hear his voice and live” (John 5:25). Therefore, he can speak to them through His Gospel, and he can command them to repent and believe, with hope of success- just as he could speak to a dead person, talitha cumi, “Little girl, I say to you, get up!” (Mark 5:41); just as He could say “Lazarus, come forth!” (John 11:43-44); and just as He could say to the paralyzed man, “Arise, take up your bed, and go to your own house” (Matthew 9:6).
The Gospel Mystery of Sanctification, pp. 71-72