怎么理解这句英文?and if you,being evil,know how to give good gifts t

怎么理解这句英文?
and if you,being evil,know how to give good gifts to your children,how much more shall your heavenly father which is heaven,give to those who ask him?这句话怎么理解?其实这句话是出现在一篇完形填空中,说：有个男孩想要父亲买车,父亲却在他毕业那天送了一本《圣经》给他.他生气的离开了家,并且好多年不理他父亲.然后有一天他回家,却得知父亲去世了,无意中又翻开了那本当年他生气而扔下的《圣经》,就看到了上面的那句英文,和夹在书中的车钥匙.很感人的一篇文章,可是就是不能理解这句话,