The plain inference here is that he who doesn't overcome shows that he really doesn't believe in his heart. And the natural result is that he does not receive these things promised. That is, he is not saved because he won't accept the Lord Jesus as his Saviour when it comes to the fire test.
There are without doubt thousands in the Church who will be left behind on the earth when our Lord Jesus catches up His own. This does not mean necessarily that they will be lost. There will be another opportunity of being saved for those living on the earth at that time. The Kingdom will be a wonderful time of salvation. There will be a continuous revival of the realest sort going on everywhere all the time.
But these would not have the blessed privilege of fellowship with the King in the Kingdom, nor the blessedness of fuller resurrection life at this time. That is reserved for those who by grace have believed on the Lord Jesus, during His absence and continued rejection, in spite of the fire of opposition.
It is notable that the Thyatiran message speaks of great tribulation coming to that Church if it continue unchanged. And that the Philadelphia Church is to be kept through "the hour of trial, that which is to come upon the whole earth." Throughout the Scriptures mention is made of a time of persecution coming at the end. The common term for it is tribulation. It is called the great tribulation. There will be more to be said about this again.
It is possible that it will be found that this Patmos message will have special significance during that trying time at the end. But it should be noted that it fits into the spirit of opposition that is always found where there is true, faithful witnessing.
The tribulation itself will be the time of intensest opposition carried to the extreme of violent persecution. It will be the climax of conditions always present, wherever there is faithful witnessing. Faithfulness to Christ always arouses opposition.
The test of whether we really accept Christ and believe Him is not in anything we say. It is not even in what we are in our lives when all goes smoothly. It is in what we are in our lives when opposed, when it costs criticism, ostracism, petty persecution, or more outright persecution. This is our Lord's test of acceptance of Himself.
We have had many definitions of what it means to believe on the Lord Jesus Christ. And these have been helpful in clearing the air and helping us to a simple acceptance of Him. These definitions have touched chiefly the inner part of faith, the part we are conscious of.
Here is another definition. Here is the last word on the subject, the authoritative word, from our Lord Jesus Himself. It tells what faith is in its outward working, the part the crowd sees. The faith that accepts Jesus as Saviour accepts Him also as Lord.
That faith naturally rings true to Him under all circumstances. It rings truest and clearest whenever opposition to Him is aroused, whether the opposition of indifference, of criticism and sneer, or of persecution.