It is by Christ’s mighty accomplishment that this grace is available to us, an accomplishment far greater than that of Moses through whom the law was given. The law could be given by one who was only a man, because all that was required was its publication - the Ten Commandments and the Old Testament ceremonial.
We must cultivate utmost dependence upon Christ in everything we do, we depend upon him. And let there be some, hopefully much, grace and truth flowing from us too towards others. Grace and truth. That is Christ. May it be reflected in us: always gracious, always courteous, always ready to forgive, always compassionate; and truth: always genuine, always true, always faithful. Grace and truth.
Does this verse mean that there was no grace in the Old Testament? John is talking not so much about the contrast between law and grace, and if you overemphasise that you give the impression that the Old Testament was all law and only the New Testament is grace, and that in the Old Testament they did not have any grace. But it would be wrong to give that impression because they did have grace in the Old Testament. All the grace and mercy that was shown by God to repentant sinners throughout the Old Testament awaited the coming of Christ. People could be forgiven throughout the Old Testament, but the great transaction that would purchase their salvation waited for Christ himself.