Imagine, it’s 4 am in the morning, you recently had a breakup with your girlfriend and it wasn’t a really peaceful breakup. She calls you and her voice suggests, in fact affirms that she had been crying from hours. We all you human after all so you feel bad and all she asks is “Do you still love me?”, “I can’t live without you, just tell me that you love me”. 
Any sane and intelligent human being will be scared about the consequences that may come his way after he says, “Sorry, I don’t love you anymore”. You can never predict what may come your way next, a cut down nerve or a bottle of rat poison imbibed. So what would you do at that moment? Say the truth or try to console her with the lie? No doubt that 1 lie will make you go through prevarication but isn’t it better than taking away a life which was special to you at one point of time in your life.
Lies are never righteous but they are better than bitter truths at times. Many other instances can just state that how they are better but the decision lies in your hands, you can choose to kill or to save a life.