Having an excellent virtual team is the important thing in FIFA 15, but win the game is the ultimate thing you need to complete. To have an excellent ultimate team you may buy player packs from the virtual store, priced variably starting from 0 coin/FIFA point for a starter and gift pack till approximately 100,000 FIFA coins/2,000 FIFA points for a jumbo rare player pack. If you don't have enough coins or points there are actually some shortcuts that might increase your winning chance that will take you to victories.
The thing that most gamers probably do is take advantage of the game creator's (Electronic Arts) policy that allows the use of real money to buy FIFA points, which as you know can be used for a player pack purchase. You can buy the points in the virtual shop for the game on console or FUT web app if you play it on your PC. You can pay by credit and debit card, Skirll Wallet and Boku SMS for PC game as well as credit card, PayPal and pre-paid for console game (Playstation and Xbox).
However, there are many other shortcuts that are not facilitated by EA that EA considers as cheats, such as the so-called bid jumping where you need to create another different account to place a high bid on a player you sell in order to make the character look much higher in terms of value that someone might want to bid for even a higher price, and coin buying with real money from coin sellers by using auto buyer bot software.
This sort of things is considered illegal by EA. The game creator has declared a war against cheaters that mostly materializes in the new EA rules of banning or resetting of the gamer's FUT account, with or without warning if found cheating. However, this can't make a sense as EA itself facilitates game pack buying with real money, which perhaps has been its main source of income and that for that reason it's very unlikely for EA to withdraw.
Yes, buying game packs with real money, even if it is facilitated by EA, is cheating. If someone new to FUT out there who has a considerable amount of money is willing to spend his money for buying a 2000-point jumbo rare player pack, then it is not a fair game for a beginner or even a conservative FUT game expert who decided not to use real money at all for winning matches. These cheating issues will always be around as long as EA itself facilitates cheating and tries to make self-justification by blaming on cheaters alike for cheating, for it will make it difficult for EA to create a fair policy for every gamer of FIFA 15.