The Holy Bible says man was born in sin and therefore it can be assumed that sin is inherently in man's nature. Nevertheless it's an undesirable nature that our Heavenly Father desires we rid off our being. The act of ridding ourselves off this undesirable nature is called "Repentance" and it's the only way to salvation of our souls that consequentially will earn us eternal life in the heavenly presence of our Creator.
For ages since God created man on Earth He has sent us great men inspired to the work of preaching repentance and the salvation of souls but much success was not achieved in this regards until He sent to us His only begotten son our Lord and savior Jesus Christ that He may by the sacrifice of His blood on the cross and the Holy gospel bring unto all humanity heartfelt repentance and a right to become inheritants of the kingdom of God.
True repentance and salvation of souls started with the ministry of our Lord Jesus Christ where He gave us the holy gospels which basically are teachings on how to live right in accordance with the laws of God. Christianity started with Christ Jesus where He taught man to live in emulation of His works and words and for the first time in the history of the religious world the conscience of man was made more sensitive to wrongs hitherto treated with an attitude of oversight. Man was taught to do unto others only what he wouldn't mind being done unto him
To this day even thousands of years after the establishment of the Christian mission by Lord Jesus man still battles against the inherent nature of sin. Repentance has been proven to not be a day's affair. It's not possible to become absolutely repentant and sin free overnight. Repentance is an attitude of resolution to always do right no matter the promptings of our sinful nature to do otherwise. Like a baby learning to walk, no matter how many times he may fall while mastering the use of his little legs he's resolved to pick himself up and walk again. We must as Christians resolved to live a repentant life cultivate an attitude of steadfastness to act right at all times no matter the promptings of our sinful nature. With time it becomes second nature for us to always question our conscience and act right and at such a stage in our spiritual life repentance has been achieved by an attitude of resolution thus positioning us for an inheritance of eternal life in the presence of our Heavenly Father.
I pray for all who read this, genuinely in search of repentance to be strengthened in Faith in Christ Jesus our saviour to live above sin and all temptations that leads to sin in the mighty name of Christ Jesus I pray. Amen.