A few years ago, I was laying in a hospital room, in my 2nd week of a lengthy stay following a bad accident. They had poked me so many times, that it was getting almost impossible to get a new IV every couple of days, and hard to draw blood. Finally, a doctor explained they could put in a central line, that they could give meds, fluids and draw blood through and not have to stick me anymore, except the procedure was dangerous and could even be fatal. Then he looked me straight in the eye and said, "but I'm pretty good at it". I replied, "I like a cocky doctor, go for it". In my experience, if they are that confident in their skills, I'm pretty satisfied.
There is a difference between cocky and confident though, cocky carries it a little toward arrogance and conceit. But confidence is a really good thing, especially when we get it from God. John, after describing our faith in Jesus as the son of God says, "I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life." So that we 'may know', or have confidence. We don't have to wonder or hope it is so, we know it completely. (1 John 5:13)
Paul in speaking about perseverance says, "... being confident of this, that he who began a good work in you will carry it on to completion until the day of Christ Jesus." (Phil 1:6) Paul in Romans says, "For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord." Again, he is 'convinced', confident. So are we. (Rom 8:38-39)
And finally, Jesus says, "...My sheep listen to my voice; I know them, and they follow me. I give them eternal life, and they shall never perish; no one will snatch them out of my hand." Jesus gives us assurances, and we can be confident they won't waver or change. (John 10:27-28)
Throughout scripture, we are given example after example. We can be confident, we can be secure, and we know our Holy Father would not give us any false assurances in His Word. It is not necessary for us to 'hope so' when we have every assurance from the One who cannot fail us.