Miracles were Evidences of a Divine Commission
Source: TTT
Exodus 4:1–5
Then Moses answered, “What if they do not believe me or listen to my voice? For they may say, ‘The LORD has not appeared to you.’” / And the LORD asked him, “What is that in your hand?” “A staff,” he replied. / “Throw it on the ground,” said the LORD. So Moses threw it on the ground, and it became a snake, and he ran from it.
Mark 16:20
And they went out and preached everywhere, and the Lord worked through them, confirming His word by the signs that accompanied it.