I am a confirmed Lutheran, and in Confirmation, we are taught that when we ask Christ to be our personal savior, the Holy Spirit has already worked on our hearts to allow us to open it. Asking for Jesus to be our Savior requires that we acknowledge our sinfullness and our inability to pay the price for our sins without accepting His blood sacrifice. We must confess that we are sinful to be accepted into heaven.
We are also taught that Jesus died once to forgive all of the sins of those who believe, so if you sin after you ask Christ into your heart, you are still forgiven, as your salvation is secure. So, if someone dies before confessing their sins since the last time they asked for forgiveness, but in their hearts they love Jesus as their savior, that doesn't affect their salvation.
When you say friendship with God, I think of fellowship, sort of like a spiritual conversation. Even when we have salvation, if we continue to dwell in our sins and refuse to ask for forgiveness, we are not in fellowship with God. Salvation is the presence of the Holy Spirit in our hearts. When we sin and don't confess it individually, we don't lose the Holy Spirit or salvation, but we choose to ignore God's friendship for the moment.