Q & A on Grace

"As by one man's disobedience many were made sinners, so also by one Man's obedience many will be made righteous. ... Where sin abounded, grace abounded much more, so that as sin reigned in death, even so grace might reign through righteousness to eternal life through Jesus Christ our Lord. Romans 5:19-21

Q: Can every believer have grace enough to keep him free from sinning?   

A:Yes.

It is given for "the perfecting of the saints" (Ephesians 4:12, KJV),

for the building up of the body of Christ. This grace is given to everyone where sin abounds; and it brings salvation to everyone to whom it is given.

As boundless grace is given to everyone, bringing salvation to the extent of its own full measure, then if anyone does not have boundless salvation, 

Q: why is it?

A: Plainly, only because he will not take that which is given. 

Q: If sin still reigns in anyone, where lies the fault?

A: Only in this, that he will not allow the grace to do for him that which it is given to do. 

By unbelief he frustrates the grace of God." E.J. Waggoner