“But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,”
King James Version (KJV)
1:20 But ye, beloved, not separating, but building yourselves up in your most holy faith - Than which none can be more holy in itself, or more conducive to the most refined and exalted holiness. Praying through the Holy Spirit - Who alone is able to build you up, as he alone laid the foundation. In this and the following verse St. Jude mentions the Father, Son, and Spirit, together with faith, love, and hope.
Jude 1:20 Building up yourselves on your most holy faith. Instead of separating from the faith. Praying by the Holy Spirit. See PNT "Eph 6:18".