Sorry to say this, but the answer is “no”.

People who claim to be Christians, but who persist in their pet sin(s), are not true believers. True followers of Jesus Christ simply do not make a practice of sinning:

We know that God’s children do not make a practice of sinning, for God’s Son holds them securely, and the evil one cannot touch them. (1 John 5:18, NLT)

The bible warns that there are many who fellowship within church walls, but whose conduct exposes them to be really enemies of Christ, and whose destiny is damnation:

For I have told you often before, and I say it again with tears in my eyes, that there are many whose conduct shows they are really enemies of the cross of Christ. They are headed for destruction (Philippians 3:18-19a, NLT)

The bible warns us not to be deceived, that a person (regardless of whether he/she professes to be a Christian) will reap what he/she sows, and that those who sows to please their flesh will reap destruction:

Do not be deceived: God cannot be mocked. A man reaps what he sows. Whoever sows to please their flesh, from the flesh will reap destruction; whoever sows to please the Spirit, from the Spirit will reap eternal life. (Galatians 6:7-8, NIV)

It is therefore important for the disobedient Christian to stop sinning, to put off the old self, and to put on the new one:

22 You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires; 23 to be made new in the attitude of your minds; 24 and to put on the new self, created to be like God in true righteousness and holiness. (Ephesians 4:22-24; NIV)