I was saved when I was a kid but since then I have done some bad things. Have I lost my salvation?
Let’s make sure you had salvation first before we answer your question. If you had humbly come to Jesus and prayed that you believed that he came down to earth as a man, yet fully God, and died on the cross to take the punishment for your sin and then rose from the dead to conquer sin, and you admitted that you were a sinner and asked for God through Jesus Christ to forgive you of your sins and asked Him into your heart, then you are saved.
Now for the question…Can someone lose their salvation? Answer is no you cannot. Here’s why. You can’t undo what Jesus did on the cross. If you could, then your sins would be more powerful than God’s love and mercy and more powerful than what Christ did on the cross. All of your sins, past sins, present and even future sins are forever forgiven. Nothing can change that, not even your behavior.
For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord.
We as Christians will at times sin. But God will continue to forgive us those sins if we are sorry because of what we did. That does not take away from our eternal forgiveness but helps us grow spiritually. Repentance will help us grow closer to God and dependent on Jesus to live a life that honors Him. A desire to study and meditate on the Word of God will help us focus on God’s will for our lives.