Jude 15:20

But you, beloved build yourselves up on (the foundation of) your most holy faith (continually progress, rise like an edifice higher and higher), pray in the Holy Spirit.

Praying in the Holy Spirit is an advantage given to us by God. We build ourselves up when we pray in the Holy Spirit and increase our foundation of faith. We may not know what we are saying, but God does and answers prayers we didn’t even know we had. So, use the advantage given to us by God to help strengthen us here on earth.