Lawful, Lawfully - Vine's Expository Dictionary of New Testament Words
Lawful, Lawfully[ A-1,Verb,G1832, exesti ]
an impersonal verb, signifying it is permitted, it is lawful" (or interrogatively, "is it lawful?"), occurs most frequently in the synoptic Gospels and the Acts; elsewhere in John 5:10; John 18:31; 1 Corinthians 6:12; 1 Corinthians 10:23; 2 Corinthians 12:4; in Acts 2:29, it is rendered "let me (speak)," lit., "it being permitted;" in the AV of Acts 8:37, "thou mayest," lit., "it is permitted;" Acts 16:21; in Acts 21:37, "may I," lit., "is it permitted?" See LET, MAY.
Note: For ennomos, See C, No. 2, (under LAW).
[ B-1,Adverb,G3545, nomimos ]
"lawfully," is used in 1 Timothy 1:8, "the Law is good, if a man use it lawfully," i.e., agreeably to its design; the meaning here is that, while no one can be justified or obtain eternal life through its instrumentality, the believer is to have it in his heart and to fulfill its requirements; walking "not after the flesh but after the spirit," Romans 8:4, he will "use it lawfully." In 2 Timothy 2:5 it is used of contending in the games and adhering to the rules.