Most Christians refer to the Bible as the foundational "source of strength" that is provided by God to help them do everything in life. It is called "The Word of God" and is believed to be holy, God-breathed, and relevant.
Within the New Testament there are several scriptures referred to in the Christian church for how to deal with sin and temptation. 1 Corinthians 10:13 says:
No temptation has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can endure it.
Believers refer often to this scripture as a source of encouragement that though temptation does exist, God always provides an opportunity to overcome it.
In addition to several applicable scriptures, Christians also refer to the example set by Jesus Christ as a source of strength for overcoming sin and serving others. Each of the four gospels gives a slightly different account of the life of Jesus on Earth, which is characterized by servant leadership, unconditional love, and putting others' needs first. What has now been termed "The Golden Rule" originated in the gospel of Matthew:
So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets (Matthew 7:12, emphasis added).
Jesus' example, while he was on Earth, is a picture of practicality and a standard by which Christians seek to live. Because Jesus was human, Christians believe that he experienced all the same emotions, temptations, and pain that humans experience today. But because he was also God, Christians believe he was perfect. Believers use Jesus' example as a source of strength and encouragement to overcome sin and to serve others.