God rewards us

Mt 6:4(God rewards our giving for Him)

    ⁴ so that your giving may be in secret. Then your Father, who sees what is done in secret, will reward you.

Mt 6:18(God rewards our fasting for Him)

¹⁸ so that it will not be obvious to others that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you.

Col 3:23, 24(God rewards our work for the Lord)

  ²³ Whatever you do, work at it with all your heart, as working for the Lord, not for human masters, ²⁴ since you know that you will receive an inheritance from the Lord as a reward. It is the Lord Christ you are serving.

Mt 16:27(when God will reward us? He will reward each person, when He comes)          

 ²⁷ For the Son of Man is going to come in his Father’s glory with his angels, and then he will reward each person according to what they have done.

Psalm 62:12(Why God rewards us? His love is unfailing)

¹² and with you, Lord, is unfailing love”; and, “You reward everyone
   according to what they have done.”