See to it that no one misses the grace of God and that no bitter root grows up to cause trouble and defile many. [Hebrews 12:15]
It's always so difficult to see bitterness when you are feeling it, yet so easy to see in other people. Bitterness truly is a root that grows deep if you allow and the poison seeps everywhere. It even spills out to others around you, if you aren't careful. Search your heart earnestly. When you identify a thorny root, pray for the person who is the source of bitterness and allow God to do His work. It's not fun being consumed by poison.