The longer answer, the answer that takes time to explain and implement, is that everything we do, say, and think, flows out of what we believe to be true. The tricky part is figuring out what is actually going on under the surface.
I want you to picture a fruit tree. The fruit is the evidence of what kind of tree you have growing. Our tree is sustained by roots that dig deep. Our heart is contained in these roots, and as Luke 6:45 tells us, it is out of the overflow of the heart that the mouth speaks.
The anger, fear, or bitterness that sneaks out of our mouths reveals what is really going on inside our hearts. We need to examine our behavior, thoughts, and actions from the viewpoint of Christ. In John 15:5, He tells us that apart from Him we can bear no good fruit. Sounds a little far-fetched, because we like to think we are in complete control. Sometimes complete control is actually complete denial.
Apart from Christ, we can try and try but we can't change our hearts ourselves. It is the relationship with Jesus Christ that changes us from the inside out; the process requires our reaching to Him, but He does the work. An obedient heart and openness to something that may be contrary to what we believe to be true may be necessary for His fruit to bloom in us, but it will bloom.
As you evaluate your own words and actions, what do they say about the real you? What do you really believe about the people and world around you, about yourself? Before you say "That's just the way I am", offer your heart to Jesus and ask Him to change it, from the inside out.
"The fruit of the Spirit is love, joy, peace, patience, kindness, goodness,
faithfulness, gentleness, and self-control. (Galatians 5:22)"