If you know Jesus—really and truly know Jesus, not just know of him—you’re gonna want to follow him. You’re gonna want to do as he teaches, and actually try to obey his commands instead of shrugging them off with, “Well, they’re nice ideals, but they’re not gonna be practical.” You’re gonna want to be good.
Goodness is a fruit of the Spirit. A rather obvious one: God is good, so shouldn’t those who have the Holy Spirit in us be likewise good? Shouldn’t he encourage us to be good, empower us to do good deeds, be gracious to us when we drop the ball and help us return to goodness? Shouldn’t he point us in the direction of sanctification, of living holy lives, unique from the rest of the world—where goodness is a huge factor in why we’re unique?
Likewise if you don’t wanna be good, not only do you lack the Spirit’s fruit: You’re probably not even Christian. And yes, bluntly saying so has a tendency to really offend people: “Goodness doesn’t make you Christian! That’s legalism. How could you say that?” Well I didn’t say that. I said you have to want to be good. You have to make the effort. You’re gonna suck at it in the beginning; everybody does; it gets easier with practice. And I didn’t say goodness makes you Christian; only the Holy Spirit does that. But the lack of goodness, or substituting it with hypocrisy and hoping no one will notice, indicates the Holy Spirit isn’t in your life—and if he’s not there, you’re not Christian. Period.
Let’s not be naïve. “Obey Jesus” is a hard lifestyle choice. The world is against us. Christianists have gone to a lot of trouble to swap real obedience with their cheap knockoff, and sometimes they’ll fight goodness just as hard as Satan itself. They’ll claim Jesus’s commands were nullified by a new dispensation, or they’re only meant to describe God’s kingdom after Jesus returns—not before. They’ll claim our resistance to evil is really works righteousness and legalism; that trying to be better is another form of pride; that our commonsense interpretation of God’s commands is extremism, whereas the proper way to interpret them is to water ’em down till they’re nothing but water.
Plus our own selfish tendencies are gonna fight us. And yes, the devil might fight us too… but you’ll find the devil’s far easier to beat than your own flesh. We start off with a lot of ingrained bad habits, and conquering ourselves has to be done first. Which a lot of people never bother to do. Most of us simply relabel all our bad behaviors with Christianese names, and presto-changeo, we’re fixed now! But widespread popular hypocrisy is still hypocrisy.
Still, if we have the Holy Spirit in us, we’ll want to do better. And we’ve got to trust him to help us out with this. We absolutely can’t do it alone. God offers us power to live for him. Grab it with both hands. You accepted his salvation. Now accept his sanctification.