God speaks through life, through creation, by His Word finally and fully in His Son Jesus Christ. If we have not heard God speak it is because we have not listened. Like those living in the days of God's loudest and clearest call, watching the life and miracles of Jesus Christ we can 'stop our ears so that we do not hear.! In Acts chapter 8 God speaks again. We observe God speaking Personally to Philip, a man sensitive to the personal guidance of the Spirit of God, moving obediently the call of God on his life and movements. We observe too the transformation in the Ethiopian eunuch as God speaks to this man through His word. He is transformed from ignorance to intelligence, darkness to light, from desperate seeking to settled conviction that he has found the answer to all of his searching, not in a place or a religion but in God's Son Jesus Christ. God speaks clearly in Acts chapter 8 through His Word, by the ancient prophets. Philip is able to open up the meaning of Isaiah chapter 53, showing that this ancient prophecy speaking of one led as a lamb to the slaughter as the sin bearer and sin sufferer and presented as the source of eternal salvation and the forgiveness of sins speaks of none other than Jesus Christ. It is by Jesus that the offer of Isaiah chapter 53 is made good; that by knowing Him, that is trusting Him, this righteous servant will make many right. God's fullest revelation lies here of course; the revelation of His Son Jesus Christ (Hebrews 1:1).
For those deaf to the still small voice of God, unwilling to open God's Word and dismissive of Jesus Christ, God has one other ongoing means of communication to a world deaf to His grace; that of changed lives. Baptism is a water shed moment in a person's life. For Israel in the book of Exodus it separated them from the world's old system in Egypt. In the days of John the Baptist, baptism drew a line between the old sinful ways and the new life of repentance. To the Corinthians in chapter 10 it was a water shed not so much form the world and it's system, nor simply sin but from the demonic and Satan, but perhaps the greatest of all demands present in baptism is the call to personal consecration, the leaving of the old life of self behind and the commitment to live the new life in Christ, by God's grace (Romans chp 6).
Yours by Grace in Christ
Dr J Stewart Gillespie