Since Jesus is God and is holy, why would He eat and associate with sinners?
All Have Sinned
The Bible tells us that all of us have sinned. There is no one who hasn’t sinned. In fact, that’s our predisposition; to sin and to crave the desires of the flesh. The Apostle Paul, under the inspiration of the Holy Spirit, correctly stated that, “None is righteous, no, not one” (Rom 3:10b). Paul may have added the “no, not one” to cover those who believe they’re the exception, so I think Paul would say there are no exceptions to this. He goes on to write that “no one understands; no one seeks for God” (Rom 3:11). This is inclusive, as he says “no one” twice. If a person claims to no longer be a sinner, my question is, what do you do with 1 John 1:8, 10 that say we are all sinners, and to say otherwise is to make God out to be a liar. And, why are you not already in heaven? The Bible destroys any notion about self-worth or being worthy in ourselves to be saved. God’s Word says, “All have turned aside; together they have become worthless; no one does good, not even one” (Rom 3:12). All certainly means all…and includes both you and me.
Jesus’ own righteousness is the only way that we can stand before God. It is through His shed blood that God cannot see our sins anymore. It was “For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God” (2 Cor 5:21). It wasn’t the sake of our good works, which are nothing more than filthy rags to God (Isaiah 64:6). Sadly, there are many modern day Pharisees who do not think they need Jesus. Today and in Jesus’ day, there were those “who trusted in themselves that they were righteous, and treated others with contempt” (Luke 18:9). The lame, the sick, the poor, and the diseased weren’t even allowed into the temple, but listen to Jesus’ sharp rebuke of those who think they can stand before God on their own merit; “You are those who justify yourselves before men, but God knows your hearts. For what is exalted among men is an abomination in the sight of God” (Luke 16:15). They might serve in their church, their community, and even donate to ministries, but they cannot trust in these things to save them. Most people you speak to on the street would say, “I think I’m a good person,” but when held up to the Law and the Light of Perfection (Jesus Christ), they (and we) all fall infinitely and impossibly short of God’s glory (Rom 3:23). Why then was Jesus accused of eating with sinners and Publicans (Mark 2:15)?
Sinners and Tax Collectors
Perhaps none were more despised by the Jews than the tax collectors, or the Publicans. They could easily extort more taxes than were legally due, and often they did. Tax collectors were rich, just as most of the Jewish religious leaders were, so even the Jews didn’t associate with tax collectors, not to mention sinners (of by the way, they were one!). Most considered sinners as law breakers, or those who didn’t conform to the Mosaic Laws. They believed that righteousness could be attained through the works of the law, but the problem is, none of us can keep the law perfectly. It’s just not possible (James 2:10). They didn’t realize that “the law made nothing perfect” (Heb 7:19). We all stand guilty before a holy God and He demands perfection before we can enter the kingdom, but thanks be to God, the perfection that God demands, God supplies through Jesus Christ (Acts 16:30-31). He is our only hope, our only chance, and our only way (Acts 4:12). The law cannot ever hope to justify us (Rom 3:20). It is only through Jesus’ own righteousness that our perfection comes. Of course we’ll still sin this side of heaven, but we will, over time, sin less, but the good news is, It was “in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation” (2 Cor 5:19). Clearly, this was not possible through the law. The religious who thought they didn’t need God’s righteousness were in greater need of it than the sinners and tax collectors who they despised.
Jesus and Sinners
If Jesus did not associate with sinners, I would have missed the kingdom. I was a sinner long before He was my Savior. I was drawn by the Father to Christ (John 6:44), so I can’t even take credit for my coming to Christ. I did not choose Him; He chose me (John 15:16; Eph 1). Since Jesus associated with sinners, we too must associate with sinners and the “Publicans” of our day. Of course, we can’t run with them, but we can run to them and be used by God to point them to Christ. God came to us as sinners and we must go to other as sinners. If Jesus had avoided sinners, truly none of us would have been saved. He would have had to avoid all of humanity since we all have sinned. Jesus says, “Come to Me” (Matt 11:28), and not, “Come to Me after you’ve gotten your act together” or “after you’ve broken that addiction.” No, He says, “Come to me, all who labor and are heavy laden, and I will give you rest” (Matt 11:28). Jesus says it is far better to “Take my yoke upon you, and learn from me, for I am gentle and lowly in heart, and you will find rest for your souls” (Matt 11:29). There is no rest in law-keeping, not that we intentionally break the law, but we let God do what only God can do, and that is to take our sins upon Him.
Why would Jesus eat with sinners and why would He associate with tax collectors? For one, I was a sinner when He came to me. I am glad He didn’t avoid me because I was a sinner or I would have never been saved. You must admit that God did not save us because we were infinitely valuable, but because of the love of God (Rom 5:6-10) and Jesus’ infinite worth. If you’ve trusted in Christ, then Jesus must have associated with you…a sinner…and just like me, you thank God for that; hopefully, every day.
Here is some related reading for you: Are Christians No Long Sinners? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.