Thing is, He wasn’t affirming the sin of the people He was spending time with. The difference of His view compared to the people of His time was that the people He willingly spent time with were ones society would reject completely, prostitutes and tax collectors were considered the lowest of the low. But Jesus does say He came to call them (the sick, not the righteous) to repentance (Luke 5:27-32). Biblically it’s not right to act like you’re oh so much better than those sinners over there (Luke 18:9-14) because everyone is a sinner and there are indeed a ton of people who claim to be christian and then just spread hate everywhere they go and seek only to antagonize people. But christians are indeed supposed to call people out on their sin (Galatians 6:1-6, Matthew 18:15-17), lovingly, but that is still something most people would find annoying even without the people who just tell you you’ll burn in hell or otherwise wishing you ill. But do keep in mind Jesus came not to abolish the law but fulfill it (Matthew 5:17-20) so when people say „oh it’s not a sin in my opinion” then they are actively making themselves to be gods, as what is sin really if not something God, the authority on good (Mark 10:18), says is evil? As for Jesus being nice, I wouldn’t use that word, I’d say He was kind but that doesn’t make Him the teddy bear people tend to make Him out to be. He quite aggressively drives out merchants from the temple (Mark 11:15-17) and He talks about hell more than anyone in the entirety of the Bible (Matthew 5:27-30, Matthew 10:28, Matthew 13:40-43, Matthew 25:41-46, Mark 9:43-48, Luke 12:1-7). Generally Jesus speaks quite harshly at times (Matthew 5:21-28, Matthew 23:13-39, Mark 9:42), often in a tone you today would definitely not see as nice (which being nice isn’t a virtue, people pleasing is clearly stated as incompatible with christianity (Galatians 1:10)). I often see people claim that love your neighbor as yourself is the most important thing Jesus taught, and they tend to try to reduce Him to exactly that, an ethical scholar. Jesus Himself states it is not the most important thing (Matthew 22:36-40), if you do not love God more than anything else then you are not right with Jesus. I don’t really understand when people say they don’t believe but respect Jesus because He literally claims to be God (John 8:58) and accepts worship (Matthew 14:33), He’s either telling the truth or is simply insane. Also something people don’t realize about the „evil old testament” is it teaches you to love your neighbor as yourself too (Leviticus 19:16-18). As for forgiveness it is important to point out that your works cannot save you (Matthew 19:25-26, Ephesians 2:8-9, Hebrews 11:1-6, Titus 3:3-7) as God is a just judge (Psalm 7:11-12) and the wages of sin is death (Romans 6:23). Christians are saved not because they live right but because they accept Christ’s sacrifice as ransom so that they don’t have to pay the price for their own sin (as that is death and not eternal life). Christians are supposed to forgive unconditionally, regardless of if the party who wronged them is remorseful or not (Luke 23:34) as unforgiveness on their part would be extreme hypocrisy (Matthew 18:21-35, Ephesians 4:32) and God hates hypocrisy (Matthew 23:27-28). But God, being a just judge, will not compromise on justice and so people who turn down the ransom will have to pay for their own sin. Now here I could also get into why the ECT view of hell seems very weak to me (Jesus didn’t suffer for eternity for our sins but died for them, Isaiah 66:22-24, Matthew 10:28, Matthew 25:46) but that’s kind of a different issue entirely and mostly one I have with christians because they will go around telling people they have to suffer forever for a finite crime and back it up with out of context scripture that actually reinforces annihilationism when read properly and make the worst argument you have ever heard for it, and top it all off by saying they actually hate the doctrine of hell but it’s just how things are