In my opinion learning opening lines won’t help you improve your chess much, unless you already have reached a high level of play. The reason for this is that getting an edge in the opening won’t mean that much if you spoil it in the middlegame. Besides that you won’t be able to remember those opening lines unless you understand the positional ideas behind them.
For players under 1500 it’s of very little value to memorize opening lines. Above that level it is necesary to know some opening theory, but not much. Above 1800 things become different. The chance that you will retain that edge that you got in the opening becomes bigger when you play stronger. But still also then the emphasis of your training should be understanding tactics and positional chess.
I do understand that to many of you learning opening lines give you a sense of control. But you should understand that this sense of control is just an illusion. Once you get out of book in a tournament game you will have to show that you truely understand the positional ideas of chess.
Understanding positional concepts and recognizing tactical patterns are the base of chess development. Just like you can not build a house without a solid foundation, your knowledge of opening will only be usefull if you first work on a solid understanding of positional chess. Without this foundation you will be wasting your time.
I don’t mean that you should not learn anything about openings. Of course we all need to have a basic knowledge of the openings that we play. Just don’t exagerate by spending to much time studying openings while it’s a much more rewarding investment to study strategy and tactics.