If you want to be Biblical, a believer does in fact have a “license to sin” (only in the sense that the gift of eternal life cannot be forfeited). No sin that a believer commits can ever jeopardize one's Eternal Security. To teach otherwise is to negate the gift of God and teach a false Gospel of self-righteousness. Salvation is the gift of God, based upon Christ's imputed righteousness to our account (and not any good of our own). We are saved by grace through faith (Ephesians 2:8,9). Salvation is receiving, not giving.