We frequently see the word "tarry", or a form of that word, usually in reference to a seeming delay of Christ's appearance at the rapture. The expressions, "if the Lord should tarry", or, "if the Lord tarries", are most often used. I must admit that I have occasionally applied them in that context as well.
Some will also try to use those phrases when referring to Jesus’ return at His second advent. However, Scripture teaches that at that time He will return to earth (Rev. 19:11-16), along with the angelic hosts and His previously raptured believers (Jude 14; Rev. 19:14), to end the Campaign of Armageddon - climaxing the seven years of horrible tribulation events. Jesus’ return at His second coming will be swift and sure, it will be with forceful purpose, and His timing will be perfect without any delay. He has set a day for judging the unbelieving world (Acts 17:31), and that judgment will happen exactly as prophesied without hesitation.
Webster's Dictionary defines "tarry" in the following way: tarry 1a: to delay or be tardy in acting or doing b: to linger in expectation : to wait 2: to abide or stay in or at a place.
We need to understand that God does not view time as we do. Everything He does is done exactly on His schedule, and is according to His plan. Christ's appearing in the clouds to gather all believers up to Him at the rapture (1 Thess. 4:14-17; 1 Cor. 15:51-52; John 14:2-3) will not be late, either - nor will it be delayed. The rapture timing will be precisely as God pre-ordained it to happen, and not one minute later.
Hebrews 10:37b NKJV
And He who is coming will come and will not tarry.
2 Peter 3:9 NKJV
The Lord is not slack concerning His promise, as some count slackness, but is longsuffering toward us, not willing that any should perish but that all should come to repentance.
Although God has pre-planned a specific moment for the rapture, that event will be people significant rather than time sensitive, as we understand time. God desires that all would choose to follow Him and not perish, but sadly, most will not respond to His plea (Matt. 7:13-14). Our Omniscient God knows the last Gentile who will repent, confess Jesus as Lord, and who by faith alone will receive His free gift of salvation during this age of grace.
Romans 11:25 NKJV
For I do not desire, brethren, that you should be ignorant of this mystery, lest you should be wise in your own opinion, that blindness in part has happened to Israel until the fullness of the Gentiles has come in.
When the body of believers (the church) has been filled with the final Gentile being saved in this age, then, the rapture will happen. After believers have been suddenly caught up and taken away as Scripture has promised, God will turn His full attention toward Israel and the Jewish people. A Jewish remnant will have the scales peeled from their blind eyes, they will mournfully repent of their sins against Almighty God, and they will finally accept Jesus as their true Messiah.
It is not for us to know the day or the hour for the rapture. Ever since Pentecost, all believers have been commanded to watch, pray, and be ready - expecting it to take place at any time. That command is even more relevant for us today. Believers need to be aware that even while they are reading this, the final person to be saved might only be a heartfelt prayer away from having his name entered into the Lamb's Book of Life. Now, that is an exciting thought!
If the rapture was deemed imminent almost 2,000 years ago, then, just imagine how much closer we are today to that great event. Yes, just as He has promised, Jesus will come for us very soon...and He will come quickly without warning. However, those who are watching for Him will be ready when it happens.