The children of Israel where in Egypt to come out of that land,God you signs via Moses to tell the Egyptian that he is God to lead the children of Israel out of that land.There were signs like the plagues.That was a sign that Moses was a prophet. The children of Israel came out of the land that confronted the red Sea.God told Moses to stretch forth his rod to divide the red Sea,it was a sign. Joshua walk round Jericho to bring that city down.The city fell down,it was a sign. Moses brought out water from the rock,that was a sign that Moses was a prophet. Marah water turning sweet was a sign. David deliving the children of Israel out of the hands of the enemy was a sign.David was a prophet Jesus performed many miracles in the land of Israel,the children of Israel could not believe that Jesus was a prophet.Those miracles Jesus performed were signs that he was a prophet. There are fake prophets,the Egyptian magicians als