A spirited Bangladesh pulled off an upset 79-run victory in the first ODI on Thursday to take a 1-0 lead in the series.
"This loss is a bit shocking for us and it's hurting a lot. Yes, they played better than us but we are still a better team. Their cricket is improving day by day but we are on a different level," Raina was quoted as saying by bcci.tv on Friday.
The left-handed batsman, who hit a run-a-ball 40 while chasing a stiff target of 308, added that the hosts had outplayed them.
"We didn't play well. But we have two games left and we need to put in all our energy in making a strong comeback. One defeat doesn't make us a bad side. As Ravi (Shastri) told us, the way we come back will show our character."
Considering India's strong batting line-up, Raina feels the target was achievable. The Indians, who got off to a good start, lost wickets regularly to be bundled out for 228 with four overs to spare.
"We should have chased it, especially given the strength of our batting line-up. But their debutant left-arm pacer (Mustafizur Rahman) bowled really well and the two breakthroughs that Taskin (Ahmed) gave them in the form of Shikhar (Dhawan) and Virat (Kohli) was game-changing.
"After that we never really managed a good partnership besides the one between Ravindra Jadeja and me. That hurt us," he said.
India skipper Mahendra Singh Dhoni and Bangladesh pacer Rahman were fined for breaching the ICC's Code of Conduct after the two were involved in a physical contact during the match. Dhoni was fined 75 per cent of his match fee, while Mustafizur was docked half of his fee.
Asked if the debutant bowler getting in the batsman's way was a distraction, Raina said, "It would have been disturbing had one of our batsmen got run-out because of that. He collided with Rohit Sharma and then MS Dhoni.
"Anyone could have been seriously hurt. He has to learn to stay away from the pitch when the batsmen are running. The umpires need to have a chat with him about it. If he doesn't change this habit, it will be very difficult for him."
Image: India captain Mahendra Singh Dhoni (left) with team director Ravi Shastri.
Photograph: Philip Brown/Reuters