Hebrews 7:26 records God in Jesus is holy and blameless, unstained by sin, undefiled by sinners, and to Him has been given the place of honor in heaven.
In a pluralistic world Christianity is maligned because it denies any means to heaven besides Jesus. This is because if the Christian story is true, that God sacrificed Himself as payment for the disobedience of humanity, then no amount of good works by humanity can be sufficient otherwise God wasted His effort.
While Islam also makes exclusive their religion for obtaining heaven, theirs is based upon obedience to their way rather than the love of God demonstrated in His personal sacrifice. Another similarity between these two religions which also demonstrates their marked contrast is the idea that God remains undefiled by sinners.
For Islam, this status is maintained by staying aloof from humanity and not getting too close to them. It is also the reason they insist upon absolute conformity to their rules less they defile the holiness of their god.
Jesus, God as man, was undefiled not by separating Himself from humanity but by not surrendering to the temptations all humanity faces. Jesus was tempted in every way we are to defy God, He just never surrendered to the temptation.
By remaining undefiled by evil He remained the perfect sacrifice for humanity able to exchange His life for ours so that we too can become acceptable to God. Most of our temptation comes from others though our own nature likewise craves the temptation.
Pornography is done by others, displayed by others but feeds our own lusts. We steal from our neighbor who has because inwardly we want the same status, benefit or comfort.
Jesus was pure on the inside so did not give into outside temptations. This is why the Christian God judges the heart of people, He is not fooled by outward forms of obedience, He measures the motive and true nature of our being.
This is how we know Christianity is true rather than Islam and other religions that measure only outward behavior but ignore the attitude of the heart.
Christians are to be like God: holy, blameless, unstained and undefiled.
We remain undefiled when we love people not by doing the same things they do that displease God but when we lead them in doing the things that please God.