"has given, however trifling it may seem to you, and be safe. “Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.” Whosoever will willfully break one command cannot in spirit and in truth keep any of them. He may claim that, with the exception of what he may regard as slight deviations, he keeps them all; yet if he willingly offends in one point he is guilty of all. 5T 434.1"
"For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all."
EGW directly quotes and elaborates on the principle found in James 2:10.