I saw this sentence in a train advertisement for a job placement agency:
いまとサヨナラしなければ、出会えないあなたがきっといる。
I don't sense a future tense at all in the independent (latter) clause because the verb is simply いる rather than a "can" form like 〜える/〜れる/〜ける。The sentence feels disjointed as the tenses don't agree.
I feel that the following sentence expresses the same thing, but with a better match between the clauses:
いまとサヨナラしなければ、もう一人のあなたと出会えない。
Translating the original sentence literally to English as:
If you don't say goodbye to the present, there is a you that you will never meet.
sounds just as wrong because of the "is". It should be "there will be a you that you never meet".
I understand きっと to mean "certainly", but does きっといる here serve as a future tense?
EDIT: Inserted missing "you" in translation from dainichi's comment. Revised title.