Sexual temptation and staying pure

Temptation itself is not sin - Jesus 'was in all points tempted like as we are, yet without sin' (Hebrews 4:15). God promises that 'there hath no temptation taken you but such as is common to man...

but will with the temptation also make a way to escape' (1 Corinthians 10:13). Scripture's repeated counsel is to flee, not negotiate: 'Flee also youthful lusts' (2 Timothy 2:22); 'Flee fornication' (1 Corinthians 6:18), as Joseph literally ran from Potiphar's wife (Genesis 39:12).

Guard what you take in (Psalm 101:3; Philippians 4:8), stay accountable to other believers (James 5:16), and walk in the Spirit, for 'ye shall not fulfil the lust of the flesh' (Galatians 5:16). Purity is not earned perfection but a direction of the heart that God empowers by grace.