Can Prayer Change Things?

Many times when you pray, God hears it. He always hears our prayers and always hears us when we call on Him. Many times He'll gives us what we need, like healing, guidance, an answer. Other times God will tell us to do something or to follow His direction to make something happen. So yes, it does

100%. Consider Moses' intercession before God: Exodus 32:11-13

Exodus 32:11-13 - New Revised Standard Version, Anglicised Catholic Edition (NRSVACE)

<11> But Moses implored the Lord his God, and said, ‘O Lord, why does your wrath burn hot against your people, whom you brought out of the land of Egypt with great power and with a mighty hand? <12> Why should the Egyptians say, "It was with evil intent that he brought them out to kill them in the mountains, and to consume them from the face of the earth"? Turn from your fierce wrath; change your mind and do not bring disaster on your people. <13> Remember Abraham, Isaac, and Israel, your servants, how you swore to them by your own self, saying to them, "I will multiply your descendants like the stars of heaven, and all this land that I have promised I will give to your descendants, and they shall inherit it for ever."'

The word implore here in verse 11 is a very strong verb, Moses is asking God, begging Him really, to stop from his affliction of the Hebrew people and give them another chance.

And then Exodus 32:14, right after this prayer - it says in most translations "so" or "and so". The NIV uniquely has "then", presumably because they didn't like the idea of God doing what Moses asked because he asked (edited)

Exodus 32:14 - New King James Version (NKJV)

<14> So the Lord relented from the harm which He said He would do to His people.

This is very much like what the saints are doing for us at all times, thank God