"In this world you will have tribulation but be of good cheer I have overcome the world." Jhn 16:33.
"... thou art the Christ, the Son of the Living God" Mt. 16:16.
The Bible says that our faith (which cometh by hearing and hearing by the word of God-Rom. 10:17) is the victory that overcomes the world in 1Jhn. 5:4 and in verse 5 of the same chapter we are made to understand that our faith is that Jesus is the Son of God or that He is the Christ, the Son of the living God (if you compare Mt.16 :16 with 1Jhn. 5:1,4-5 and also Jhn. 1: 12,13)
The question then becomes, how is our faith the victory that overcomes the world? Or rather, how does our faith function as the victory that overcomes the world? we turn to Mt. 16: 15,16.
In the above verses, Jesus asks His disciples who they believed Him to be or who He was and Peter replied that He is the Christ, the Son of the living God. Jesus' response to Peter's answer is that God had revealed it to him (Peter) and that upon that rock (which rock is the acknowledgment, the belief that He is the Christ, the Son of the living God) He would build His church and the gates of hell shall not prevail.
Jude 20 then tells us, "but you beloved building up yourselves on your most holy faith praying in the Holy Ghost"
This lets us know that our faith functions as the victory that overcomes the world by being the foundation; firm and unshakable foundation, upon which our lives are built "... for it was founded upon the rock"
The kernel of the matter, from the above, is praying in the Holy Ghost. What does it mean to pray in the Holy Ghost?
To pray in the Holy Ghost could mean either to pray in the language of the Holy Spirit or in words which the Spirit communicates/teaches which is the same as praying as the Holy Ghost gives utterance (which is the same as praying in tongues or with the spirit for in Acts where it is first recorded that they spoke in tongues we are told that they each spoke as the Spirit gave them utterance; it could also mean praying in tongues (praying with the spirit) and then praying with the understanding for this is equivalent to prophesying according to 1 Cor. 14:5 and Peter-2 Pet. 1:21- when describing prophecy in the OT says prophecy came not in the time of old by the will of man but holy men of God spoke as they were moved by the Holy Ghost.