
Jesus had been addressing the causes of sin. It wasn’t rules like handwashing, and it certainly wasn’t what you eat. He said food goes in one side and out the other. Check out what Jesus taught His disciples when they asked him to explain His teaching.
“And he said, “What comes out of a person is what defiles him. For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person.”” - Mark 7:20-23, ESV.
The truth is, we have enough sinful tendencies already inside us to defile us. We have unsatisfied flesh, greedy eyes, and a pride that wants to rear its ugly head constantly. Those things are in us from birth. As long as we curtail their efforts to sin by denying their temptations, we can stay undefiled.
But the moment desire comes into the picture, and we refuse to squelch it, we activate our sin nature and defile ourselves. This is the progression of sin. See James 1:12-15 for the Biblical proof of this. Jesus’ point is that sin is triggered in us, not put in us, when we disobey man's religious laws.
We should not feed those impulses, though. It is still wrong to put pornographic images into our heads and seek every material possession. We should not do things to elevate ourselves either. All of those things will feed our unsatisfied flesh, greedy eyes, and prideful desires. We can become defiled if we allow the world's triggers to cause us to sin.
So guard your eyes, be content with what you have, elevate others above yourself, and keep a healthy layer of scripture in your brain to cover what is already there. That is your only fighting chance to stay undefiled. The Holy Spirit will see your efforts and assist you in this work. It’s hard, but it is possible with His help. In the end, Jesus will remove all of that junk from inside you, and you will be able to finally rest from that fight. - Pastor Mike
BTW, I just lost a food fight. I guess dinner's on me!