For many the word passion connects with the word lust.. However in 1 Peter 1.14 ‘passion’ seems to refer to the ardent, fervent attempt to keep Moses law without knowing the Lord Jesus Christ. It is a tragedy that still continues today among Orthodox Jews – passionate zeal for reading and keeping the Torah, yet rejecting Jesus Christ as the Lord from heaven.
This also happens in other religions. The sincerity and passion of many is admirable but zeal without knowledge is dangerous. Even so among Christians. Some people develop a passion for the correctness of their own group.. Others have an extreme unbalanced emphasis about a particular doctrine or practice. The apostle Peter quickly turns the minds of the believers to God who is HOLY. He calls on the disciples to obey Him and be conformed to Him in thought, belief, behaviour and conduct.
Peter goes on to show the holiness which is complete in God is the foundation of God’s dealings with humanity.
1 Peter 1:16 – God is the Father who judges impartially – holy
Verse 18,19 –He is the redeemer who understands the lostness of humanity (holy assessment), and He is the one who stepped in to pay the ransom price – the precious blood of Christ. Such an expression is meaningless apart from the holiness of God.
Verse 20 – The extreme value of the ‘Lamb’ is referred to – His pre-existant perfection and purpose. After the death of the Lamb (Jesus Christ dying on the cross), God in His holiness raised Him from the dead and has given Him the greatest glory, the highest place.
By this God has established for us a hope beyond law keeping and ceremony – in the living Lamb of God.
John writes of the heavenly vision "I saw in the midst of the throne a Lamb" Revelation 5
The theme of the Lamb runs through scripture and would be good for you to study.