Just before Jesus died on the cross he said in Mathew 27:46, “MY GOD, MY GOD, WHY HAVE YOU FORSAKEN ME?”. I have interpreted this as Jesus quoting Psalms 22. A Baptist friend of mine told me, "no, no, Jesus said this because he was briefly separated from God due to the sin of man”.
Does the Church have an official teaching on this? Or as a Catholic, due we have some liberty here?
This can get a little complicated, but I don’t think it has to get that compicated to answer your question.
Basically, Protestants often subscribe to a belief called penal substitution. This belief holds that Jesus atoned for our sins by suffering the
very same punishment, in every way, that we deserved - going to Hell. Hell is eternal seperation from God, so they believe that when He died on the cross, Jesus actually went to Hell, and so was seperated from God.
Now there are a lot of problems with this. First, Jesus wasn’t in Hell eternally; He rose on the third day. The answer Protestants will give to this is that since Jesus is infinite, even one second in Hell for Him is enough for all of eternity for us. However, this doesn’t work, because if Jesus was seperated from God, then He wasn’t infinite anymore, and so He couldn’t fulfill eternity in Hell for all of us.
This leads into the real problem with the idea: God is not divisible. God is one God in three Divine Persons - the uncreated Creator. If Jesus ever was seperated from God, that means He would stop being God for a moment, but if He was uncreated, He could not stop being God, because what makes God God is that He is uncreated. That is what seperates God from us - He is uncreated, we are not.
The other thing is that that for one thing to be seperated from something, the two things must be different. If Jesus was seperated from God, then He was different from God, so we would have two Gods, not one.
Suffice it to say, if Jesus was ever seperated from God, that would in some way mean that either He wasn’t really God - He wasn’t really uncreated - or that He is actually different from the God He was seperated from, so we would have polytheism.
So Jesus was quoting Psalm 22.