13 When tempted, no one should say, "God is tempting me." For God cannot be tempted by evil, nor does he tempt anyone; 14 but each one is tempted when, by his own evil desire, he is dragged away and enticed. 15 Then, after desire has conceived, it gives birth to sin; and sin, when it is full-grown, gives birth to death.
16 Don't be deceived, my dear brothers. 17 Every good and perfect gift is from above, coming down from the Father of the heavenly lights, who does not change like shifting shadows. 18 He chose to give us birth through the word of truth, that we might be a kind of first fruits of all he created. (from NIV)
You must always be prepared to be tempted and understand where your temptations come from, they come from within you, from the lusts of your heart and sometimes trick you into believing the lie that if it feels good do it.
You need to decide to who you will trust. Will you trust yourself or the character of God and look for the promises of his word?
The bible specifically warns us to resist temptation, sin, and evil, that sometimes it can be a challenge to resist. Satan is tricky and will appear as an angel of light and make the temptation seem ok. Look here in Isaiah 1 or 1 Peter 5
1 Peter 5:8-11
8 Be self-controlled and alert. Your enemy the devil prowls around like a roaring lion looking for someone to devour. 9 Resist him, standing firm in the faith, because you know that your brothers throughout the world are undergoing the same kind of sufferings.
10 And the God of all grace, who called you to his eternal glory in Christ, after you have suffered a little while, will himself restore you and make you strong, firm and steadfast. 11 To him be the power for ever and ever. Amen.