Does being under grace mean we can sin freely?
No. Being under grace does not give license to sin. Scripture teaches that grace is not license, and John writes to believers, "these things I write unto you, that you sin not." Although sin is always less than God's grace, that never grants permission to sin freely.
Les teaches that the believer is under grace, not law, but he stresses that grace is not license. John addresses believers as his little children, not the unbelieving world, and writes so that they sin not. The fact that sin is always less than God's grace does not give us permission to sin. John begs the believer, "sin not, don't sin," and then adds, "but if any man sin," showing the concern is not to excuse sin but to instruct believers.
My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous:
For sin shall not have dominion over you: for ye are not under the law, but under grace.
More Questions
Does being under grace give a believer a license to sin?
Because believers are under grace rather than law, grace is not a license; even though sin is always less than God's grace, that still does not give a license.