100. What, then, does God require of us in His holy Law?

Perfect purity and holiness in all our thoughts and desires, words and acts.

James 2:10. Whosoever shall keep the whole law, and yet offend in one point, he is guilty of all.

Matt 5:48. Be ye therefore perfect, even as your Father which is in heaven is perfect.

101. What does God say of all his commandment?

I the Lord thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me; and showing mercy unto thousands of them that love me, and keep my commandments.

That is,

God threatens to punish all who transgress these commandments; we should therefore fear His wrath, and do nothing against them.

On the other hand He promises grace and every blessing to all who keep these commandments; we should therefore love Him and trust in Him, and gladly do according to His commandments.