"The friend does us a true kindness who tells us of the things in our character, habits, manners, which appear as blemishes, although many people have too much vanity to be told of their faults. They resent it as a personal insult when one points out any blemish in them. But this is most foolish short-sightedness. To learn of a fault is an opportunity to add a new line of beauty to the life. Our prayer each day should be that God would show us our secret faults, whatever messenger he may send to point them out, and then give us grace to correct them." ~J.R. Miller
Do you have friends like this, who are willing to and do point out sin in your life? I feel really blessed by the Lord to be able to say confidently that yes, I do! :D If you don't, pray that the Lord would bring such people into your life, as I can't tell you how much it has helped me in my walk with the Lord over the years.
Also, I saw this video. It certianly gave me a wake up call to see how much time I spend on meaningless things, and how little time I really have left. It really made me think: how am I using my life? I am using every valuable minute of it to the glory of God and making Him known, or am I squandering it? I'm afraid I'm guilty of not seeing the time I have here as limited and often wasting it, but dear brothers and sisters in Christ, let us not be like this! Let us see each and every moment as an opportunity to draw ourselves and others closer to our Saviour.
God bless you all!