The Vikings are fighting to retain their Super League status after a poor campaign so far left them in the bottom four.
They started the Qualifiers as the worst-placed Super League side and they were then beaten by Warrington Wolves last time out.
Widnes face Halifax, Featherstone, Leigh, Hull KR, London and Catalans in their remaining fixtures and Betts admits his team need to beat the Championship clubs.
He told Sky Sports News HQ: "The must-win games are against Championship sides.
"Whether it's the second or third game, you've got to beat the Championship sides. We can't hide from that fact.
"We know they're going to be competitive and are striving for something more while we're trying to protect something. That creates a different kind of focus.
"Ultimately, every single game against a Championship side is a must-win."