God is invisible. He hides Himself and we are commanded to seek Him. Although He remains mysterious and inaccessible, God has issued a testimony of who He is, what He is, what His will is, what His ways are, what His purpose is, what pleases Him, and what displeases Him. We can see that this testimony, the Divine witness of God, is all-important. Apart from it mankind is ignorant and stands in peril of being destroyed by Divine judgment and wrath.
The Lord Jesus Christ is the only true Witness of God. We can behold the invisible God in the Person of Christ. We can learn about God from who and what Christ is. We can learn about God from what Christ says. We can learn about God from what Christ does. What Christ is, says, and does constitute the witness, the testimony, the expression, the Word of God.
He who does the will of God abides forever. He is a faithful and true witness because God in Christ has entered him and the true Light now shines from him. The hidden, invisible God has found another witness of Himself. Another place of abode in the Father’s House (which is Christ) has become occupied for eternity.