Here is a quick and easy way to explain Calvinism. Calvinism is like telling both of your children, "Let's go out for ice cream", and on the way there you throw one of them out the car window.
But Arminianism says that 20% or perhaps as much as 60% or 80% of the kids dumped from the car made a wise and timely decision before it was too late about how they were going to hit the curb or fall over the bridge, so that's how salvation is fair and how even in the worst of circumstances, God will have a sampling of every family on earth. See there, that mangled kid made it into college, therefore you and yours has zero excuse! Somehow, I think that when the Scriptures speak of having no excuse when it comes to Judgment Day, it's sorta talking about an instinctive but very rudimentary knowledge of good and evil, but most especially of Who God is, so that you'll even know what He's talking about, and Who It Is That's Addressing you, rather than the tales of the self made millionaires of society who've overcome impossible odds.
It's not talking about performance based righteousness with God. Zero excuse is in knowing your Creator when you meet Him and that He is completely independently righteous as the righteous judge to lead into joy or into gnashing of teeth so that all of us will ultimately get along and do things together His Way. Sowing and reaping isn't applicable to one's own eternal state. That God settled by God's Seed and the resurrection of that Seed rather than our puny genetically modified ingredients. Sowing and reaping governs whether we're going to have another day of Hell, fear, anguish, bad company, wilderness, frustration, emptiness, confusion, or whether we're going to be on the steady [though sometimes seemingly impossibly slow] increase in our characters, relationships, callings, wholeness, vision, contentment, clarity, green pastures, and still waters.
And both versions of the world we make here for ourselves tend to grow like the type of bamboo that I heard about one time where you water it for 4 or 5 years with it seemingly having zero growth and it's either in the 5th or the 6th year when the thing grows 90ft in that year. Jesus was kind in using corn and mustard seed illustrations, but many of us have had the reality of that bamboo where bad habits were doing zero to us and then everything went wrong all at once, even in areas where the carnal mind would say that it can't possibly be related. And some of us are finally experiencing the good of something that just looked at us for decades without really doing anything but sitting there, and now the milk and honey won't stop flowing like a tsunami. Jesus' usage of grape vines in His illustrations probably comes closer to reflecting the reality of most of our situations. Not much to speak of those first few years, but then WOW!!!