Whether a Roth IRA, Traditional IRA, or no IRA, taxes will be figured on the 7000. With the Roth or No IRA, you pay the taxes, if any, at the end of this tax year. With the Traditional, 7000 is deducted from your income for this year for figuring taxes, but pretty much all withdrawals later are counted towards your taxes, including any gain on investment. Could be a good deal, if you know you're going to have low income and be in a low bracket when you retire. But who wants to make that their goal?
The Roth is good for all kinds of other reasons. The big one is that when you withdraw from the Roth at a later time, none of that is taxable income, not even the gain. In that sense, the Roth can save taxes.
Back when I was working, I put every penny I could into Roth IRA's and 401k's, and am now glad that I did. I now have good savings that I can draw out at any time without being taxed, or choose not to draw out. With a regular IRA, they would force me to draw some out at a certain age, and I would pay taxes on that.