means,

Clean and clear;
Free from sin and corruption.
Free from moral defilement; holy.
Also: genuine; real; true; incorrupt.
(as, 'pure religion', James 1:27)

Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.
Philippians 4:8