There are a number of things wrong with this. First, it's utterly dismissive of my disbelief in god. No one asked if you will pray for me. Imagine if I came to you and said "God doesn't exist" without anyone asking, it would be considered intolerant, right?
Also let's not ignore how performative it is, no one will actually know whether you will pray, and if you do and believe in God's power to change me, you don't need to tell me, just pray. It's just a passive-aggressive remark for people to feel good about themselves.
Also, if you point it out they will gaslight you and say you fear God's words or some nonsense like that. I wouldn't be surprised if someone took a screenshot of this post and made a christian edit out of it, because that's the only way to make cringe things look not as cringe.