He promises heavenly riches to those who accept Jesus and serve God. Riches could mean three things.
First, riches can mean earthly wealth.
Second, riches can mean heavenly wealth, riches that are stored up in Heaven for those who serve and follow him. The more obedient you are, the more riches God stores up in Heaven for you.
Third, riches can mean spiritual blessings, such as to be rich in spirit. God can reward your obedience by giving you knowledge, or wisdom, or discernment, or healing, or even just overall happiness. The list goes on and on.
Riches does not always have to mean money. God can, and does sometimes bless those financially who serves Him, but not always. Sometimes instead of a financial blessing, He may give you a spiritual blessing. It all depends on what He wants for you and you life, and however He does bless you, you can be sure that it is for the best.
As far as finances, and really everything in life goes, God has promised us He will always meet our needs in this life. That does not always include our wants. We may want more money, but He may only provide just enough to get by. He may do this to strengthen your trust and faith in Him, or for a variety of other reasons.
So, being rich with money really doesn't have anything to do with whether God favors a person or not. What I mean is, wicked people can be rich and followers of God can be poor. But whether he realizes it or not, the follower of God is more blessed than the wicked. Whatever blessing God pours out upon the follower of God will ALWAYS outweigh the things of the wicked. Just look at salvation. Even if all throughout your life you have nothing but just enough food and provisions to survive and even if you are homeless, if you have accepted Jesus as your savior and do your best to be obedient to God, your place is in heaven when you die. And really, what is one lifetime measured against all of eternity? When you are in heaven after this life, do you think you're going to care about the years of suffering you had in this life? Of course not, because you will be with your Father in Heaven, happier than you can imagine, and you will never have to deal with anything negative ever again. That is the plan of God for His children.
I hope this helps. If you have any questions, feel free to ask. God bless.