These Sealed Ones are the "First-Fruits" on the restored nation of Israel, not the first-fruits of the Church.

          These 144,000 sealed ones are called virgins.   The fact that they are spoken of as not having been 'defiled with women' shows that they are either all men of the character of Paul the Apostle, who didn't marry, or most likely persons of either sex, who kept themselves from fornication which was the sin of the Great Tribulation.