the time was right

And they were both righteous before God, walking in all the commandments and ordinances of the Lord blameless. And they had no child, because that Elisabeth was barren, and they were now well stricken in years. And it came to pass, that while he executed the priest's office before God in the order of his course, according to the custom of the priest's office, his lot was to burn incense when he went into the temple of the Lord." Luke 1:6-9

Zacharias and Elizabeth were described as righteous, blameless, old, and childless.

"And they had no child, because that Elisabeth was barren, and they were both well stricken in years...but the angel said unto him, fear not, Zacharias: for they prayer is heard, and thy wife Elisabeth shall bear thee a son, and thou shalt call his name John." Luke 1:7&13

Like most married couples, Zacharias and Elisabeth desired and prayed for a child.

"And there appeared unto him and angel standing on the right side of the alter of incense. And when Zacharias saw him, he was troubled, and fear fell upon him. And the angel said unto him, fear not Zacharias:for they prayer is heard, and they wife Elisabeth shall bear thee a son, and thou shalt call his name John....And after those days his wife conceived and hid herself 5 months, saying, thus hath the Lord dealt with me in the days wherein he looked upon me, to take away my reproach among men." Luke 1:11-13, 24-25

Zacharias and Elisabeth had probably prayed for many years that they would be blessed with a child. However, Heavenly Father did not grant them this blessing until the time was right to accomplish his purposes. This example can help us remain faithful and avoid discouragement when our sincere prayers are not immediately answered in the way we desire. We may wish to have children or wish those children to turn their hearts toward God. We may wish security or health or liberty. God's time is not our time and His purposes will only be fully understood on our judgement day.