With freedom, comes responsibility and obligation. Just because we are free from sin with respect to our salvation, does not give us the right to pursue a life of sin. There are repercussions with respect to the quality of our life.
Jesus Christ went to the cross, and there He paid the price for sin. That price, or punishment, was what was accomplished on the cross. Forgiveness, was not a part of that package.
Forgiveness requires a recognition of ones fault, and the admission of that fault to God the Father. Thus we have the principle of confession. And this is taught in 1 John 1:9, which states if we confess our sins, then He forgives, etc.
The very first time we believed in Christ, that faith belief was automatically accompanied by the recognition of our sinfulness, and the need for a Savior. With salvation, we were automatically entered into fellowship with God.
After salvation, of course our life continues, and we commit sins, which removes us from fellowship with God. In order to recover that fellowship, we confess our sins. And that is a repetitive routine that we are mandated to abide by day by day throughout the rest of our life while we are here in this world.
The state of being in fellowship, is the environment in which our spiritual life functions.
And to complete our self, we need to be in fellowship while we pursue our spiritual life, through our daily study and application of Bible doctrine.
To sin, and therefore be out of fellowship, would prevent that advancement within the spiritual life.
Therefore, salvation does not give us the right to do anything we want, but more so places the responsibility and obligation on us for avoiding sin, and advancing in our spiritual life toward spiritual maturity.
The grace of God, is not the freedom to sin, but an opportunity to advance.