Christ has given us no assurance that to attain perfection of character is an easy matter. A noble all-round character is not inherited. It does not come to us by accident. A noble character is earned by individual effort through the merits and grace of Christ. God gives the talents, the powers of the mind; we form the character. It is formed by hard, stern battles with self. Conflict after conflict must be waged against hereditary tendencies. We shall have to criticize ourselves closely, and allow not one unfavorable trait to remain uncorrected.
Let no one say, I cannot remedy my defects of character. If you come to this decision, you will certainly fail of obtaining everlasting life. The impossibility lies in your own will. If you will not, then you cannot overcome. The real difficulty arises from the corruption of an unsanctified heart, and an unwillingness to submit to the control of God.
Source: Bible Universe