We are justified by faith.That salvation is through faith in Jesus Christ apart from obedience to the law is the doctrine of justification by faith.
How can a person both affirm and deny this doctrine?
We are sanctified by obedience to God.
2 Timothy 2:21
Therefore, if anyone cleanses himself from what is dishonorable, he will be a vessel for honorable use, set apart as holy, useful to the master of the house, ready for every good work.
1 Corinthians 1:2
To the church of God that is in Corinth, to those sanctified in Christ Jesus, called to be saints together with all those who in every place call upon the name of our Lord Jesus Christ, both their Lord and ours:
1 Peter 1:2
According to the foreknowledge of God the Father, in the sanctification of the Spirit, for obedience to Jesus Christ and for sprinkling with his blood: May grace and peace be multiplied to you.