I know i was born again christian, but i dont know how it happened that once i gave up to wrong passions and committed sin and before i used like spend a lot of time on the computer and somehow it happened that i by small steps returned to similar lifestyle than before, but of course the difference now is that i try to fight against temptations., but sometimes give up than again stand up. So how is it than once you born again you never make mistakes or you still make sins sometimes but fight it.
As a Catholic Christian it is important to know that your new birth in Christ happened at your Baptism. This is not only what your church believes, but mine as well, because this is the biblical and historic teaching of Christianity.
Our new birth is not a private experience, or a moral improvement, or a lifestyle modification. It is the objective truth and reality that we have become new people in Jesus Christ, accomplished for us not through our own moral abilities, but by the grace of God.
You can therefore look to your objective once-and-done baptism and say, with full confidence, "I am baptized". Words that make the very walls of hell shake in terror, because of the Lord who brought ruin to it by His death and resurrection. That very Lord to whom you belong, as you have shared in His death, and in His resurrection by that very baptism which makes you His. As we read in Romans 6:3-4, that we died, were buried, and rose with Christ by our baptism. You have died, and you live, in Christ, and your baptism is the testament to this objective fact.
Now to more properly address the question, can you as a baptized Christian walk away from the faith? Yes, there are dire warnings in Scripture that we should not abandon our faith, we should not walk away, we should not shipwreck ourselves. But rather, we are called to abide in Christ, to believe in Christ, to remain in Christ. Do not think of this as you needing to meet some performance criteria; but rather instead it is about recognizing that Christ is our hope and salvation.
To know what you are (what, in fact, each and every one of us is) apart from Jesus--a helpless and hopeless sinner; and to then cling to Christ, cleave to Him like a newborn child clings to his mother. For our hope and our salvation is not a lifestyle, not a compendium of moral obligations, it is not some light switch that is flipped on or off--it is Jesus Christ Himself. And now, resting in Jesus Christ, go and love your neighbor.
Behold the lusts of your flesh, and grieve over these. But do not grieve in the hopelessness. For we have One who has promised us mercy and forgiveness, repent, confess your sins, believe the good news--and now go and love your neighbor.
Mortify your flesh through repentance.
Believe in the Gospel of your salvation.
Learn to mourn over your sin not because God is cruel and holds your sins over your head to threaten you--He does not. But rather learn to mourn over your sin as a child who betrays a loving parent, as a friend who has disappointed a friend. That as we walk and fall in this life, carrying our cross, we can learn that the injuries of our sin isn't in that God's feelings are offended, or as though His nostrils flare in anger--but in that we have failed to do what our loving Father expects of us, that we have not been a brother to the least of these, and this should sadden us. But it is not a sadness that should destroy us, but a sadness that drives us to contrition, and to cleaving all the stronger to God's mercy in Jesus Christ.
I have sought in my life to regularly pray two prayers:
The first is "Lord Jesus Christ, Son of God, have mercy on me a sinner." And the second is, "Lord, crucify me." That the Lord might, in His patience and kindness, teach me through life how to die--not in a morbid sense (heaven forbid), but rather that I might learn how to die, and therefore find myself alive. That there is this paradox: That whoever seeks to cling to their life shall lose it, but whoever loses his life shall find it.
-CryptoLutheran