In a resource pack, under "assets/minecraft/models/" there are two folders called 'block' & 'item'.
Models in the 'block' folder are the ones that change how blocks placed down on the ground look like.
Models in the 'item' folder are the ones that change how items held in the player's hand/inventory look.
Usually for item models, Minecraft uses models from the block folder as a parent then changes some display values to make it look good.
If you want the item in your hand to look like the block you placed down then either name your block model exactly the same as the vanilla model you are replacing or you change the text in the item model to what you need.
Hope this helps
So I took into account your suggestion ( which was still helpful, but it hasn't changed. What has happened instead is, that the entire item block was changed to black and purple squares, but when the block is placed down, the block stays the same as it originally was. As you can see in the image.
Before putting files: http://imgur.com/a/hhdeQ
After putting files: http://imgur.com/a/kprIL
It looks like the item model in your hand (2nd pic) has the correct model but it is the textures that are messed up. I suggest opening the model file that you have for that item '.../models/item/...' and double checking your path & name for the texture file that it is supposed to use then checking if the texture follows that.
As for the block model (the one that's placed), since it doesn't seem to be replacing the default Minecraft model, your model is either not valid code or it also has a name/path that is not valid. I might need more info though on your folders, names & model code.
Alright, so i've been looking at the code, and i realized that my original resource pack had 2 different log files. One was named log, and the other named log_. Plus, there seems to be no path for leading to the texture from the texture i want to put in. Yet, the other one does. I'm very confused, and i want to add the path towards the texture, but i don't know how to do that