I think you're wrong when you say pride is a sin. I think pride is a healthy thing, because it makes us want to work harder and become a better person. I think it's good for us to take pride in our accomplishments.
It’s not necessarily wrong to take pride in something we’ve done well. This kind of pride isn’t boastful or self-centered, but is a feeling of satisfaction over what we’ve accomplished. The writer of Ecclesiastes in the Old Testament declared, “Nothing is better than that a man should rejoice in his own works” (Ecclesiastes 3:22, NKJV).
But sinful pride—the kind the Bible condemns—is far different. Sinful pride is self-centered and boastful, and makes us take credit for everything we are and everything we do. Instead of realizing that we are dependent on God, in our pride we ignore God and believe we can get along without Him. The Bible says, “In the pride of your heart you say, ‘I am a god …’ But you are a mere mortal and not a god” (Ezekiel 28:2).
The tragedy is that pride blinds us to our faults. More than that, pride blinds us to our need for God. Instead, we become self-confident and independent, and we see no reason to humble ourselves before God or seek His wisdom and help. But pride is a dead-end road, and eventually it catches up with us. The Bible warns, “Pride goes before destruction, a haughty spirit before a fall” (Proverbs 16:18).
Don’t let this happen to you. Instead, face honestly your need for Christ’s forgiveness, and for the new life He offers to all who humbly commit their lives to Him. God loves you, and life’s greatest joy comes from knowing Christ and putting our lives and our futures into His hands.