The Most Impeccable and Impactful Witnesses

If John baptized for repentance (Mark 1:4), why was Jesus baptized?

What are the important lessons from Jesus' baptism?

In regard to Jesus' baptism, what are the implications for us? What does Baptism mean?

What does Jesus mean when he says to John, His baptism is necessary to "fulfill all righteousness" (Matthew 3:15)

When else did the Father speak from Heaven and what did He say?

Is the Doctrine of the Triune God (Trinity) in the Old Testament?

How did the Holy Spirit witness to the world in Jesus day and how does He "witness" to us today? 

What happened next, after the Baptism? And what does that show us?