4. Literally, "Ye have become void from Christ," that is, your connection with Christ has become void (Ga 5:2). Ro 7:2, "Loosed from the law," where the same Greek occurs as here.
      whosoever of you are justified--"are being justified," that is, are endeavoring to be justified.
      by the law--Greek, "IN the law," as the element in which justification is to take place.
      fallen from grace--Ye no longer "stand" in grace (Ro 5:2). Grace and legal righteousness cannot co-exist (Ro 4:4, 5; 11:6). Christ, by circumcision (Lu 2:21), undertook to obey all the law, and fulfil all righteousness for us: any, therefore, that now seeks to fulfil the law for himself in any degree for justifying righteousness, severs himself from the grace which flows from Christ's fulfilment of it, and becomes "a debtor to do the whole law" (Ga 5:3). The decree of the Jerusalemcouncil had said nothing so strong as this; it had merely decided that Gentile Christians were not bound to legal observances. But the Galatians, while not pretending to be so bound, imagined there was an efficacy in them to merit a higher degree of perfection (Ga 3:3). This accounts for Paul not referring to the decree at all. He took much higher ground. See PALEY'S Horæ Paulinæ. The natural mind loves outward fetters, and is apt to forge them for itself, to stand in lieu of holiness of heart.

JFB.