I have learned that just having an infinite +2/+1 attack on tap is already one of the best things you can manage. For most Guardians, at least on normal, it means you fight at 6 and can reasonably hit most things without other setup. It is also nice to be able to run other cards besides Beat Cop and Ace of Swords. In this sense, the first ability compares favorably to Timeworn Brand. Now, this does take an extra hand slot, but does cost one fewer resource. So how does the second ability compare?
First off, the second ability is repeatable this time, though requires bless tokens and some usage of the first ability to get it off. +4/+2 is pretty good for just being able to lay the hurt into most things, and if you have some sort of plus 1 damage ability, whether through beat cop, Vicious Blow, or Enchant Weapon, you can whack a 4 health enemy pretty reliably. I would say I prefer the flexibility over the Brand.
So, is this worth running? If you are already running Bless, absolutely! The question is more, is it worth running bless to get access to this weapon? I would say, maybe... It probably isn't as good as Flamethrower, but that has to run its own support suite to be repeatable. I don't think you're going to ruin your game though if you go for this. If you want to force bless tokens just to get the spear, I'd say go for it! Guardian doesn't have great ways to get the tokens into the bag though, so you might need some help, and as always, check with your group to see if they are on board with it. But ultimately, I am glad there is another viable high-end option for using violence as the solution to all problems.