The Gospels describe times when Jesus went off alone—mostly to pray. The two most well-known times were at the beginning of His ministry when He went into the wilderness for forty days and was tempted by the Devil (Matthew 4:1–11; Luke 4:1–13) and at the end of His ministry when He prayed alone in the garden (Matthew 26:36–46; Mark 14:32–42; Luke 22:39–46). So, how do we know what happened during those times?
Matthew and John were Jesus’ disciples and it is very possible He told them about those times. Jesus was with them for over three years, teaching them and sharing life with them. It is not unreasonable to assume He told them about His time of temptation in the desert, for example. Luke specifically says he interviewed eyewitnesses to Jesus’ life (Luke 1:1–4) to write his Gospel. Mark is believed to have gotten the information for his Gospel from the apostle Peter (1 Peter 5:13). So they, too, would have had access to the information.
Additionally, Jesus appeared to the disciples after His resurrection over a period of forty days “speaking about the kingdom of God” (Acts 1:3). He very well could have filled in some of the questions they had about those times He was alone.
All else can be attributed to the inspiration, guidance, and direction of the Holy Spirit (2 Timothy 3:16). Jesus addressed this with His disciples. He said, “These things I have spoken to you while I am still with you. But the Helper, the Holy Spirit, whom the Father will send in my name, he will teach you all things and bring to your remembrance all that I have said to you” (John 14:25–26).
Clearly the times the Gospels describe Jesus’ activities while alone are times God wanted us to know about. He is capable of communicating the messages He wants us to know. Whether Jesus told the Gospel writers or the Gospel writers’ sources directly, or the Holy Spirit told the writers directly, we can trust that God has revealed to us that which we need to know (2 Timothy 3:16–17; 2 Peter 1:3; Deuteronomy 29:29).