You shall not be afraid of them but you shall remember what the LORD your God did to Pharaoh and to all Egypt, the great trials that your eyes saw, the signs, the wonders, the mighty hand, and the outstretched arm, by which the LORD your God brought you out. So will the LORD your God do to all the peoples of whom you are afraid.
Deuteronomy 7:18-19 ESV

Miracles aren’t just to convince unbelievers or to relieve someone from suffering. They are often done so that both the faithful and the unbeliever will know God’s character.