bitterness and unforgiveness

Would not bitterness and unforgiveness escape from me if I am developing into being Christ-like. "Be joyful always; pray continually; give thanks in all circumstances, for this is God’s will for you in Christ Jesus" (1 Th 5:16-18 NIV). My joy is not necessarily from my situation in life rather it a byproduct from my relationship with my Father. It is great to know it is God's will or my Father wants me to live in happiness, and I can because of his love for me.