What we're seeing now is a power struggle within the IRA. The Priest and his posse are both at the same time in cahoots with and against Jimmy n'dem, 'cause he's threatening the old way: recruiting impressionable youth from off the street to fight the war, etc.

What the Priest realizes is that the anger Jacks n' Gemma is feeling over his son can be used to his advantage in weakening Jimmy. Although Jim wants them Sons out of the way, he can't just go to war with them without taking big hits to his stock. But this move with the wee one brings all kind of shit right to Jimmy's front door. The Priest is going to try to push Jimmy out, methinks. And if he gets the confidence of the Sons, it's a much easier power move for him.

Also, these episodes are revealing some deeper ties between the Sons and the IRA. The Teller family name has been dropped a few times with significance in the Ireland scenes, and I wouldn't be surprised if we meet some of the original Irish MC real soon.