When does. Trying to convince someone become trying to manipulate someone

I had a better way of articulating it, but I went with that.

So for the longest time I felt like I shouldn't give people reasons behind an answer because you can put in the reasons behind it can sway their decisions. Also I know that I had incomplete data set. Humans do lean on each other to think and you can inject what idea and have it spread.

To attempt something more coherent. You can do propaganda when you try to reason. It's just natural to talk as if they know and just bridge the gaps in their knowledge with any old phrase