Matthew 5: 17 - 19
17 "Think not that I have come to abolish the law and the prophets; I have come not to abolish them but to fulfil them.
18 For truly, I say to you, till heaven and earth pass away, not an iota, not a dot, will pass from the law until all is accomplished.
19 Whoever then relaxes one of the least of these commandments and teaches men so, shall be called least in the kingdom of heaven; but he who does them and teaches them shall be called great in the kingdom of heaven.

EWTN