Scotland, who are one point behind leaders Poland in Group D, have not reached the finals of a major tournament since the World Cup in France in 1998.
They face Qatar on Friday as a warm up before their crunch fixture in Dublin on June 13, live on Sky Sports 1 HD, where a win would boost their qualifications hopes.
Everton striker Naismith is confident the national team now have the players to deliver on recent promise and book their spot at next summer’s finals, again in France.
He told Sky Sports News HQ: “I’ve been in squads with some great players and I’ve learned a lot from them but in terms of confidence, positivity and enthusiasm I’ve not had it much higher.
“That just comes to the fact that the quality of player in the full squad – the 20-25 guys that come along – is so high that the manager probably struggles every game to pick a starting 11.
“That is what has progressed us well. We are a group of guys who get on really well and we’ve had the stage of our careers where there has been a lot of potential but now it is time to fulfil that potential and I think we have shown that.”
Despite the fixture against the Republic of Ireland being billed as must-win, Naismith thinks every game in the Group is vital, especially against those at the top.
“Everybody has said that it is the biggest game but that’s only because it is the next game and the group is so tight,” Naismith said.
“Poland, Germany, Ireland and ourselves have all been fighting it out so the games we have got against each other, there will be a lot of eyes on us watching out for the results.
“But we’re confident with how we’ve done in the first half of the campaign and if we can continue that trend on then we’ll be close to getting to a qualification spot and that’s all we can do.”
The former Rangers striker knows how tough the trip to Dublin will be, but pointed to the side’s battling display during their previous 2-2 draw away in Poland as proof of their ability to handle the big games.
He added: “We’ve shown in Poland that we were up against it at times in that game, we came from behind to get in front and at the end we were holding on for the draw but we did that. And that could become a massive point.
“Like the Ireland game we go into, we know it is going to be tough but we’re confident. We’ve got good players who are comfortable on the ball, take the ball under pressure and create opportunities for each other.”
Watch Scotland v Qatar on Sky Sports 5 from 7.30pm on June 5 and then Republic of Ireland v Scotland on Sky Sports 1 from 4pm on June 13.