Jesus Christ encourages each of the churches to overcome, clearly implying that success within God's purpose is tied to it. God did not create us and call us into His purpose for failure. The Greek term for "overcome" here is nikáo (Strong's #3528), which means "to subdue, to conquer, to prevail, to get the victory."
Jesus indicates that Christian life is challenging. The Bible does not view the worship of God as a passing activity on which a person spends a few hours one day a week. Rather, it shows the worship of God to be a full-time responsibility, a work requiring dedication and discipline. God calls upon each of us to be "a worker who does not need to be ashamed" (II Timothy 2:15). Sin impedes proper worship.
The reasons for the use of such strong terms does not become directly apparent until the New Testament, where Jesus and the apostles give specific instructions to individual Christians on avoiding sin at all costs. The Bible's writers see us in a battle for our very lives! In whatever context it appears throughout Scripture, sin is viewed as failure—as succumbing, not overcoming. Each time we sin, we suffer a defeat in life's overall purpose.
Besides defeat, Isaiah 59:1-2 provides us with another reason why sin is perceived so dreadfully: "Behold, the LORD's hand is not shortened, that it cannot save; nor His ear heavy, that it cannot hear. But your iniquities have separated you from your God; and your sins have hidden His face from you, so that He will not hear."
This second reason is in no way secondary in importance; it is in every way equal to or greater than the sense of failure. Sin creates estrangement from God. This is extremely important because our relationship with Him is the source of our power to succeed. He created us to have an everlasting relationship with Him in peaceful and productive harmony.
God does not sin because sin destroys relationships. As sinners, we would not fit within a non-sinning relationship. Despite human reasoning to the contrary, whether the relationship is with fellow humans or with God, sin always works to produce separation. A continuing life of sin destroys any hope of oneness. It never makes matters better; it never heals. Lasting success and sound relationships are never achieved through sin.
John W. Ritenbaugh
Sin, Christians, and the Fear of God