"When the Helper comes, whom I will send to you from the Father,
that is the Spirit of truth who proceeds from the Father, He will testify about Me,"
Is there any doubt that the third person of the Trinity -- the Holy Spirit -- is critical in the life of a Christian? We need His truth to undergird us and give us the strength we need to stand up and refuse to believe the lies the world feeds us every day. God teaches us through the Holy Spirit: " But when He, the Spirit of Truth (the Truth-giving Spirit) comes, He will guide you into all the Truth (the whole, full Truth). For He will not speak His own message [on His own authority]; but He will tell whatever He hears [from the Father; He will give the message that has been given to Him]," (John 16:13 Amplified Bible).
"This strong Succourer and Friend is ‘the Spirit of truth,’ by which is designated, not so much His characteristic attribute, as rather the weapon which He wields, or the material with which He works. The ‘truth’ is His instrument; that is to say, the Spirit of God sent by Jesus Christ is the Strengthener, the Encourager, the Comforter, the Fighter for us and with us, because He wields that great body of truth, the perfect revelation of God, and man, and duty, and salvation, which is embodied in the incarnation and work of Jesus Christ our Lord. The truth is His weapon, and it is by it that He makes us strong." (Alexander Maclaren)