John 16:13

"However, when He, the Spirit of truth, has come, He will guide you into all truth; for He will not speak on His own authority, but whatever He hears He will speak; and He will tell you things to come." John 16:13

It's not hard to know the truth if You are the truth, and speaking with authority would come quite naturally if you're God! Discernment is also easier if you know, as Jesus does, what's in the hearts of men (John 2:24, 25). Though we don't possess those attributes, we do have the Holy Spirit. If we are going to continue the work of Jesus, we must yield to the Holy Spirit and allow Him to control and guide us. Then we can know the truth, speak with authority, and discern
good and evil.

We have as our guide the Spirit of truth. When Jesus promised to send the Holy Spirit, He said, "When He, the Spirit of truth, comes, He will guide you into all the truth . . . He will disclose to you what is to come. He shall glorify Me; for He shall take of Mine, and shall disclose it to you" (John 16:13-14). This promise has primary reference to the apostles, but its application extends to all Spirit-filled believers (1 John 2:20-27). The Holy Spirit is first and foremost the Spirit of truth, and He will lead us into all truth.

Truth is God's will made known through His Word. The Holy Spirit's role is to enable us to understand the Word of God from God's perspective. Jesus says, "You shall know the truth, and the truth shall make you free" (John 8:32). Hallelujah, Amen and Amen.