"When the Counselor comes, whom I will send to you from the Father, the Spirit of truth who goes out from the Father, he will testify about me. And you also must testify, for you have been with me from the beginning" (John 15:26-27)
It is the work of the Holy Spirit to bear witness concerning Jesus Christ. All the work of the Holy Spirit centers in Jesus Christ. It is His work to magnify Christ to us, to glorify Christ by taking of the things of Christ and declaring them to us.
It is only through the direct testimony of the Holy Spirit in the individual heart that any man ever comes to a true and saving knowledge of Jesus Christ (1 Corinthians 12:3). No amount of listening to the testimony of men regarding Jesus Christ, and no amount even of studying what the Scriptures say about Christ, will ever lead anyone to the knowledge of Jesus Christ unless the Holy Spirit, the living Spirit of God, takes the message of men, or the testimony of the written Word, and interprets it directly to our hearts.
It is true that the Holy Spirit's testimony regarding Jesus Christ is found in the Bible. In fact, that is exactly what the whole Bile is, the Holy Spirit's testimony to Jesus Christ. But the Holy Spirit must take His own testimony as it is found in the Word of God and interpret it directly to the heart of the individual and make it a living thing in his heart, or he will not come to a saving knowledge of Jesus Christ.
If you wish men to get such a true view of Jesus Christ that they will believe in Him, you must seek for them the testimony of the Holy Spirit, and you must put yourself in such relations to God that the Holy Spirit can bear His testimony through you. No amount of argument and persuasion will ever bring anyone to know Jesus Christ.
And if you wish to have a true knowledge of Jesus Christ yourself, it is not enough that you study the Word and what the Spirit of God has said about Jesus Christ in the Word: you must seek for yourself the testimony of the Spirit of God directly to your own heart through His Word, and put yourself in such relations to God that the Holy Spirit can bear His testimony directly to your heart.
Precious Jesus, all around me are people whom I care deeply for and who desperately need to come to know You, but they don't even realize it. May You work in my life so powerfully that they might see something of Your Spirit and be drawn to You. Amen
~R. A. Torrey~