Jeremiah 35:15 I have sent also unto you all my servants the prophets, rising up early and sending them, saying, Return ye now every man from his evil way, and amend your doings, and go not after other gods to serve them, and ye shall dwell in the land which I have given to you and to your fathers: but ye have not inclined your ear, nor hearkened unto me.
God had chosen these people and given them the promised land. They were His people and would always be His people. He had given them gifts.
The relationship was not conditional. Enjoying the benefits of the relationship however was conditional. If they decided to live in sin and do their own thing then they would lose the blessings. If they serve other gods and refused to get right with God then they would lose the blessings.
It was a matter of doing their own thing and refusing to listen to God.
How often have we been guilty of the very same thing? We do what we want and assume that God should have to give us whatever He promised.
He will give what He promised without condition but on somethings there are conditions. To enjoy the benefits of our relationship means that we will love and honor Him.