Can an active criminal have a true testimony of the Gospel?
Our Heavenly Father wants all of His children to live with him forever, so the answer is yes, even criminals can have a testimony of the gospel and can believe in Jesus Christ.
Just being a believer in the Gospel does not mean that you will never make mistakes or have lapses in judgment. Often times in our society, people mistake the word “Christian” for the word “perfect.” I’ve heard many times, “How can that person curse? He says he’s a Christian.” or “That woman cut me off in traffic yet has Christian bumper stickers. She isn’t representing her faith very well!.” The truth is that being a Christian doesn’t mean we are entitled to make poor choices, but we are forgiven for our lapses in judgment. Society expects members of our church to act a certain way, and so do other members. That’s a bit unfair. No matter what religion you are, you are not perfect and you will make mistakes.
Sadly, the mistakes we make can be grave ones. I’m not making excuses for those who commit criminal acts, but often times there are many reasons why someone would go down that path. You and I never know what someone does in their spare time away from us, nor do we understand what demons they struggle with. Just to be clear, I’m not saying any kind of antisocial behavior is justifiable. What I am saying is that sometimes it’s very surprising what people do when others are not around.
We do not always practice what we preach, nor preach what we practice. Even someone who believes in the gospel can get a speeding ticket. Sometimes someone who believes in the gospel can associate with the wrong crowd and get themselves caught up in a much worse situation. While we can, and should, judge the actions of someone, we should let our Heavenly Father judge if their faith was authentic or not.
Hope this helps a bit,