2 Corinthians 5:17

If anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new. 

Our past will try to hold us back if we let it.  That could even be a problem from yesterday if some sort of strife happened.  We have the power to choose and decide how we are going to react and control the flesh.  What being new means is the ability to recreate our lives in the image of Jesus and walk in love.  Love is like the curtain rod that everything from Jesus hangs upon.  When we are in Christ, we are a new, love creation and all the old self has passed away.