.... but you just can't make him drink! You could be Mr. Atlas, with muscles bulging from every crevice, able to use your might to push the horse's head into the water, but you could not make that horse stick out his tongue and draw in long droughts, if he had a mind not to.
And neither can Christians force someone to believe the truth in God's word. We can lead them to the truth, show them how to drink it in and find refreshment, and teach them how the Living Water would cause them to thirst no more, but we can't make them slurp it up in belief.
That is the Holy Spirit's doing. We just lead them to the trough of truth (God's Word), and He hands them the cup, offering them a way to drink it, if they've a mind to.
It's their choice. And it's nice that God lets us choose... just hard when we see that someone chooses to walk away parched. But fear not, as I was reminded twice this week - God's word never goes void "without accomplishing what I desire, and without succeeding in the matter for which I sent it" (Isaiah 55:11).
It's all in God's hands!