You put your fate in His hands,
Yes, that's part of what it means to trust in Christ.
kinda daring Him to let you get sick anyways.
No. Whether I get sick or not, God has very little to do with it.
God doesn't micromanage my life, nor the consequences to my actions.
And again, in order to build my God-given immune system, getting sick is part of the process. If I die, then I die, but God isn't the one who killed me.
Jesus would often cite the news of the day to teach a lesson. One lesson in particular is relevant here:
There were present at that season some who told Him about the Galileans whose blood Pilate had mingled with their sacrifices.And Jesus answered and said to them, “Do you suppose that these Galileans were worse sinners than all other Galileans, because they suffered such things?I tell you, no; but unless you repent you will all likewise perish.Or those eighteen on whom the tower in Siloam fell and killed them, do you think that they were worse sinners than all other men who dwelt in Jerusalem?I tell you, no; but unless you repent you will all likewise perish.” - Luke 13:1-5 http://www.biblegateway.com/passage/?search=Luke13:1-5&version=NKJV |
The Galileans were not killed because they were worse sinners than other Galileans, nor did the 18 in Siloam die because they sinned.
Jesus said they didn't, pointing out that sometimes things happen that aren't punishments from God.
In the same way, if in the process of building up my immune system, I get sick and die, it's not a punishment from God, I didn't "tempt fate," as it were, nor did I "tempt God," but it was simply coincidence.