As Christians we are not perfect, but we should strive to be. Our goal is to live like Christ. When we are short-tempered or talk of someone else in a bad light are we living as Christ did? NO. We see in 1 Corinthians 13:11
When I was a child, I spoke as a child, I understood as a child, I thought as a child; but when I became a man, I put away childish things.
As we mature in our walk with Christ we put away childish things. Things such as being easily angered or gossiping about those around us. These things will not happen overnight, but it is our job as followers of Christ to do our best in following His example.
Psalm 39:1 I said, “I will guard my ways, Lest I sin with my tongue; I will restrain my mouth with a muzzle, While the wicked are before me.”
In this verse we see David, often called a man after God's own heart, profess that he would guard his ways and not sin with his tongue, and keep his mouth muzzled while the wicked are present. This does not mean that he truly wore a muzzle. This means that he will not sin with his words while in the present of nonbelievers. Many times I see people verbally attack nonbelievers, but if God is a God of love we must treat others with love. The Lord tells us that we are to love the unbelievers just as we love the believers. If this is true why then so often do we bash them and not show them love? We want to bring the lost to Christ the best way to do that is by choosing words of love and sharing them the message of love that God has for them. When we are harm we only push them away even further
Proverbs 21:23 Whoever guards his mouth and tongue Keeps his soul from troubles.
When we guard our mouth from gossip and unkind words it allows us to show love and kindness toward those that are sometime hard to love. When we gossip it is often to judge another individual. We are told that we are not to judge man that it is the job of Christ to judge man. But how do we guard our mouth? With prayer, we see David again in pray to God for this exact thing.
Psalm 141:3 Set a guard, O Lord, over my mouth; Keep watch over the door of my lips.
We must pray for the words we use everyday. If we are in a bad situation or not we should be praying for God to speak through us always. We will often have to pray harder when we are in a position that we feel we could become short-tempered. We know that we are to be long-suffering and not give into those temptations to reply back in an unloving and unkind way.