The atonement is about forgiveness of past sins. It is not about continuing and ongoing forgiveness while in the midst of doing things we know are wrong. We are obligated by the atonement to overcome and change, Christ having declared that he will not save us in our sins, but only from them.
Consider Adam and Eve. Was it not by a single transgression that they were cast out of the garden of Eden? And did they come back into the garden a week later, or a month later, or a year later?
If Adam and Eve were cast out for a single transgression, then can we not know that the issue is that one transgression continually makes us unworthy to return to God's presence unless an atonement was made.
That is important because with Stephen Robinson's book "Believing Christ" there is a transformation of the issue from being a single transgression to being an ongoing and continuing stream of vaguely defined sins leaving the reader stopped in the tracks of his progress, believing that he is now justified as he stands, and that is good enough because of Christ. Sure, token effort is required in Robinson's account. But repentance is portrayed as something God doesn't really require. Instead, the obligation can be met by doing whatever we consider "our best" and if it is only pennies than that will be plenty enough.
Can we believe that we will be redeemed and return to God while living less righteously than Adam and Eve did while they were still shut out from the presence of God.
Do we believe that we will enjoy living with God for eternity, while not living as well as those who could not yet return to a merely Terrestrial garden where God would visit and instruct from time to time?
The path may be long to return to the presence of God, but the promise is that he that seeketh diligently shall obtain the prize. And "Believing Christ" not only teaches us that seeking diligently isn't necessary, it even discourages it, condemning individuals who are trying to "save themselves" as having rejected the atonement.
Can we offend God by striving to faithfully follow Christ? Can we reject the son in striving with our might to follow his perfect example? Is not discipleship measured by the degree to which we strive to emulate the master?
Stephen Robinson's book "Believing Christ" is actually opposed to Christ, for it condemns those who might otherwise have diligently hearkened to Christ's own command "Come follow me" as well as his command "What manner of men ought ye to be? Verily I say unto you, even as I am."
It is the book "Believing Christ" that not only does not believe Christ's own words, but drives others out of the path of heeding the words of the master himself.