Can schismatics do anything right?

Today’s Gospel is from Mt 18:15-20.  It includes the following passage:

“Again, amen, I say to you, if two of you agree on earth
about anything for which they are to pray,
it shall be granted to them by my heavenly Father.
For where two or three are gathered together in my name,
there am I in the midst of them.”

What of those in schism?  Is it possible for those who deny the Church He founded by saying to the first Pope:  “Thou art Peter, and on this rock I build My Church.” to claim to “be gathered together in My Name” while they are in schism from His Church?

Is it even probable that those who deny His Church and His teaching may “be gathered in His name”?

If not, in whose name are they gathered?  Are schismatics participating in a delusion, propped up by various passages they embrace while ignoring such foundational teachings as:  “If you do not eat My Body and drink My Blood, you do not have life in you.”

Why would anyone take the risk of offending God by asking Him for help while ignoring that clear instruction that may reasonably be interpreted:  “If you do not take Communion in the Catholic Church, you are dead to Me.”

Can schismatics do anything right?