There are no Guarantees in Poker, Any two card's can win , and any two can lose, It is all in the Lap of the Gods (Poker Gods).
Now I am not saying it is all about Luck or the lack of it, But if you do not hit the Flop Turn or River, the only way you can win is to Bluff That is part of the Skill you need, Knowing how much you can bet to convince someone you have them beat, Too small a bet and they will call, Too big and they might suspect you are trying it on, and call just to see if you are Bluffing.
Getting that balance in your betting is very important, in order to win by bluffing, Make it look like you are wanting them to call and it will do the trick if they have only a Pair or even 2 Pair depending on the size of your bet, and the size of the Pot.
I have been involved in hands where the Board has 4 suited cards, I am sitting with two pair, neither of them in the same suit that is shown on the Table, and still called because I felt something just didn't add up! Call it Luck, Call it Instinct, Call it what you like! I still called and Won with two Pair!
That came from concentrating on the hand, following the betting, and When my opponent made his River bet he was giving me
odds of around 5 to 1, Which seemed to me a good return for me to call,
Even the best players in the World have bad days, Where nothing seems to go right, Luck can make it happen for you, if it didn't you wouldn't get Amateur Players winning Tournaments, and I feel that is why Poker is so popular.