He promises to be with you
Seek good and not evil, that you may live; so the Lord God of hosts will be with you, as you have spoken (amos 5:14)
A lot of groups  and nations claim to have God on thier side. SOmetimes even the opposing sides in war both say teir cause is the one God favors. But God said that his promise is conditional: He's with you if you stop doing the wrong thing and start doing the right thing.
Easier said than done? In fact, relying on your own ability, you'll think it's impossible. Even David faild t obey God at times. But David was quick to turn back to God when he messed up. David understood what God really wanted. "You do not delight in burnt offering," he told God."The sacrafices of God are a broken spirit, a broken and contrite eart-these, O God, You will not despise" (Ps. 51:16,17). God wants a perfect heart, one that you constantly wash with repentance and forgivness.
When God says you must start doing right, He's not looking for exact perfection. He's looking for someone who really wants to obey him, who will pray like David did: "create in me a clean heart, O God, and renew a steatfast spirit within me" (Ps. 51:10). If that's what you want, He is definitly on your side.
See for yourself:
2Chr. 13:10-12; Ps. 118:5-9; Zech. 10:5