1 Peter 1:10-17 (ESV)
Concerning this salvation, the prophets who prophesied about the grace that was to be yours searched and inquired carefully,  inquiring what person or time the Spirit of Christ in them was indicating when he predicted the sufferings of Christ and the subsequent glories.  It was revealed to them that they were serving not themselves but you, in the things that have now been announced to you through those who preached the good news to you by the Holy Spirit sent from heaven, things into which angels long to look.
 Therefore, preparing your minds for action, and being sober-minded, set your hope fully on the grace that will be brought to you at the revelation of Jesus Christ.  As obedient children, do not be conformed to the passions of your former ignorance,  but as he who called you is holy, you also be holy in all your conduct,  since it is written, “You shall be holy, for I am holy.”  And if you call on him as Father who judges impartially according to each one’s deeds, conduct yourselves with fear throughout the time of your exile,
knowing that you were ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold,  but with the precious blood of Christ, like that of a lamb without blemish or spot.
Just a few thoughts regarding temptation and our pursuit of holiness that come to mind out of reading I Peter 1:14.
Even after we are saved we need to be told not to conform to sinful passions. Peter calls these passions the passions of our former ignorance. It is not the passions that are former. It is the ignorance. The passions we had when we were ignorant are still with us. They are still present. But they are the passions that we had when we were ignorant. Just because we are no longer ignorant does not mean that we no longer have sinful passions. The ignorance is gone, but the passions remain. In our ignorance the passions reigned. Now in our knowledge they do not. Now we can say “no” to them. Now we can use the things that God gives us to battle them. The commandment itself is testimony that we do not need to go where the passions would take us. This is encouraging on so many levels.
1 – Salvation does not mean that the evil passions we have go away.
2 – Salvation does mean that we no longer have to follow where the passions entice us to go.
3 – Our new found knowledge in Christ, by the Spirit, is sufficient to keep us from following our evil passions. See II Peter 1:3
4 – The Apostle Peter himself knew about the presence of evil passions that needed to be triumphed over.
5 – Temptation is not sin. We do not excuse our sins. But so often we think that being tempted is sin itself. Jesus was tempted. Peter is not saying here that the pull to isn is sin. He is saying conforming to them is.
6 – We should increase in our knowledge of God as a weapon against our own sinfulness. Conforming to sinful passions is a mark of ignorance: ignorance of God, of the Scriptures, of the work of the Holy Spirit in us, of the accomplishments of Christ for us. As Eugene Peterson puts it: “You didn’t know any better then; you do now”
7 – Do not let the presence of evil passions make you think that you are not a believer. Not fighting them would be.
Evil passions need to be replaced by good passions. It involves focus and training to fix our eyes on what is more lovely than where the passions take us. We fix our eyes on Jesus (Hebrews 12:1-2). He is to become our greatest passion. He is more lovely than the things that call us away from Him. To love God with all our heart is to have renewed passions – for Him. He is the goal. God has given us what we need in order to fix our eyes upon our better goal. He has given the Holy Spirit, the Word of God, the fellowship of the saints – the church, corporate and personal prayer and the sacraments (Acts 2:40-42).
What a great and powerful work God has done for us in Christ. Let us not be conformed to anything less.