Yes, those who believed, when he preached to them. Paul preached to the save, the Gospel of their Salvation Eph 1:13
13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise,
The Gospel is the word of Salvation to the saved ! Problem ?
If they were not saved, then the Gospel would have been hidden from them, because for the 1000th time, the Gospel is hid to them that are lost 2 Cor 4:3-4
3 But if our gospel be hid, it is hid to them that are lost:
4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.
BTW, No Paul does not hide the Gospel to the Lost, the devil does, he is the one that has blinded their minds, it states that in the passage !